Using DNA to Solve Cold Cases U.S

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U.S. Department of Justice Office of Justice Programs UY02 JULY National Institute of Justice

Special REPORT

Using DNA to Solve Cold Cases U.S. Department of Justice Office of Justice Programs 810 Seventh Street N.W. Washington, DC 20531

John Ashcroft Attorney General

Deborah J. Daniels Assistant Attorney General

Sarah V. Hart Director, National Institute of Justice

This and other publications and products of the U.S. Department of Justice, Office of Justice Programs and NIJ can be found on the World Wide Web at the following sites:

Office of Justice Programs http://www.ojp.usdoj.gov

National Institute of Justice http://www.ojp.usdoj.gov/nij

Using DNA to Solve Cold Cases

NCJ 194197 Sarah V. Hart Director National Institute of Justice

This document is not intended to create, does not create, and may not be relied upon to create any rights, substantive or procedural, enforceable at law by any party in any matter civil or criminal. Findings and conclusions of the research reported here are those of the authors and do not reflect the official position or policies of the U.S. Department of Justice.

The National Institute of Justice is a component of the Office of Justice Programs, which also includes the Bureau of Justice Assistance, the Bureau of Justice Statistics, the Office of Juvenile Justice and Delinquency Prevention, and the Office for Victims of Crime. National Commission on the Future of DNA Evidence

In 1995, the National Institute of Justice collection, laboratory funding, legal issues, (NIJ) began research that would attempt and research and development. The to identify how often DNA had exonerated Commission’s working groups, consisting wrongfully convicted defendants. After of commissioners and other experts, extensive study, NIJ published the report researched and examined various topics Convicted by Juries, Exonerated by and reported back to the Commission. The Science: Case Studies in the Use of DNA working groups’ reports were submitted Evidence to Establish Innocence After to the full Commission for approval, Trial, which presents case studies of 28 amendment, or further discussion and pro- inmates for whom DNA analysis was vided the Commission with background exculpatory. for its recommendations to the Attorney General. On learning of the breadth and scope of the issues related to forensic DNA, the By nature of its representative composition Attorney General asked NIJ to establish and its use of numerous working groups, the National Commission on the Future of the Commission received valuable input DNA Evidence as a means to examine the from all areas of the criminal justice sys- most effective use of DNA in the criminal tem. The broad scope of that input enabled justice system. The Commission was the Commission to develop recommenda- appointed by the NIJ Director and repre- tions that both maximize the investigative sented the broad spectrum of the criminal value of the technology and address the justice system. Chaired by the Honorable issues raised by its application. Shirley S. Abrahamson, Chief Justice of the Wisconsin Supreme Court, the Com- mission consisted of representatives from Commission members the prosecution, the defense bar, law enforcement, the scientific community, Chair the medical examiner community, acade- mia, and victims’ rights organizations. The Honorable Shirley S. Abrahamson Chief Justice The Commission’s charge was to submit Wisconsin Supreme Court recommendations to the Attorney General that will help ensure the best use of DNA Members as a crimefighting tool and foster its use throughout the entire criminal justice Dwight E. Adams system. Other focal areas for the Com- Director mission’s consideration included crime Federal Bureau of Investigation Laboratory scene investigation and evidence

iii SPECIAL REPORT / JULY 02

Jan S. Bashinski Ronald S. Reinstein Chief Associate Presiding Judge Bureau of Forensic Services Superior Court of Arizona California Department of Justice Maricopa County, Arizona Sacramento, California Darrell L. Sanders George W. Clarke Chief Deputy District Attorney Frankfort Police Department San Diego, California Frankfort, Illinois

James F. Crow Barry C. Scheck Professor Professor Department of Genetics Cardozo Law School University of Wisconsin New York, New York

Lloyd N. Cutler Michael Smith Wilmer, Cutler & Pickering Professor Washington, D.C. University of Wisconsin Law School

Joseph H. Davis Jeffrey E. Thoma Former Director Public Defender Miami-Dade Medical Examiner Mendocino County, California Department Kathryn M. Turman Paul B. Ferrara Director Director Office for Victim Assistance Division of Forensic Sciences Federal Bureau of Investigation Commonwealth of Virginia William Webster Norman Gahn Milbank, Tweed, Hadley & McCloy Assistant District Attorney Washington, D.C. Milwaukee County, Wisconsin James R. Wooley Terrance W. Gainer Baker & Hostetler Executive Assistant Chief Cleveland, Ohio Metropolitan Police Department Washington, D.C. Commission staff Terry G. Hillard Christopher H. Asplen Superintendent of Police Executive Director Chicago Police Department Chicago, Illinois Lisa Forman Deputy Director Aaron D. Kennard Sheriff Robin W. Jones Salt Lake County, Utah Executive Assistant

Philip Reilly Interleukin Genetics Waltham, Massachusetts

iv USING DNA TO SOLVE COLD CASES

Crime Scene Investigation Working Group

The Crime Scene Investigation Working review with a specific emphasis on using Group is a multidisciplinary group of criminal DNA evidence to solve previously unsolv- justice professionals from across the United able crimes. Although DNA is not the States who represent both urban and rural only forensic tool that can be valuable to jurisdictions. Working group members and unsolved case investigations, advance- contributors were recommended and ments in DNA technology and the success selected for their experience in the area of of DNA database systems have inspired criminal investigation and evidence collec- law enforcement agencies throughout the tion from the standpoints of law enforce- country to reevaluate cold cases for DNA ment, prosecution, defense, the forensic evidence. As law enforcement profession- laboratory, and victim assistance. als progress through investigations, however, they should keep in mind the array of DNA has proven to be a powerful tool in other technology advancements, such as the fight against crime. DNA evidence can improved ballistics and fingerprint data- identify suspects, convict the guilty, and bases, which may substantially advance exonerate the innocent. Throughout the a case beyond its original level. Nation, criminal justice professionals are discovering that advancements in DNA technology are breathing new life into old, Chair cold, or unsolved criminal cases. Evidence Terrance W. Gainer that was previously unsuitable for DNA Executive Assistant Chief testing because a biological sample was Metropolitan Police Department too small or degraded may now yield a Washington, D.C. DNA profile. Development of the Com- bined DNA Index System (CODIS) at the Members State and national levels enables law enforcement to aid investigations by effec- Susan Ballou tively and efficiently identifying suspects Office of Law Enforcement Standards and linking serial crimes to each other. The National Institute of Standards and National Commission on the Future of Technology DNA Evidence made clear, however, that Gaithersburg, Maryland we must dedicate more resources to empower law enforcement to use this Jan S. Bashinski technology quickly and effectively. Chief Bureau of Forensic Services Using DNA to Solve Cold Cases is intend- California Department of Justice ed for use by law enforcement and other Sacramento, California criminal justice professionals who have the responsibility for reviewing and inves- Sue Brown tigating unsolved cases. This report will INOVA Fairfax Hospital provide basic information to assist agen- SANE Program cies in the complex process of case Falls Church, Virginia

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Lee Colwell Darrell L. Sanders Director Chief Criminal Justice Institute Frankfort Police Department University of Arkansas System Frankfort, Illinois Little Rock, Arkansas Clay Strange Thomas J. Cronin Assistant District Attorney Chief Travis County District Attorney’s Office City of Coeur d’Alene Police Department Austin, Texas Coeur d’Alene, Idaho

Terry G. Hillard Contributors Superintendent of Police Cheryl May Chicago Police Department Assistant Director Chicago, Illinois Forensic Sciences Education Center Little Rock, Arkansas Mark Johnsey Master Sergeant (Ret.) William McIntyre Division of Forensic Services Detective Sergeant (Ret.) Illinois State Police Department Atlantic County Prosecutor’s Office Springfield, Illinois Homicide Unit Hammonton, New Jersey Christopher Plourd Attorney at Law San Diego, California

vi Contents

National Commission on the Future of DNA Evidence ...... iii

Introduction ...... 1

The Long and Short of DNA...... 5

How Can DNA Databases Aid Investigations? ...... 9

Practical Considerations ...... 13

Identifying, Analyzing, and Prioritizing Cases ...... 17

vii Introduction

In 1990, a series of brutal attacks on elder- had been convicted of shooting into an ly victims occurred in Goldsboro, North occupied dwelling, an offense that Carolina, by an unknown individual dubbed requires inclusion in the North Carolina the “Night Stalker.” During one such DNA database. The suspect was brought attack in March, an elderly woman was into custody for questioning and was brutally raped and almost murdered. Her served with a search warrant to obtain a daughter’s early arrival home was the only sample of his blood. That sample was ana- thing that saved the woman’s life. The lyzed and compared to the crime scene suspect fled, leaving behind materials evidence, thereby confirming the DNA intended to burn the residence and the database match. When confronted with victim in an attempt to conceal the crime. the DNA evidence, the suspect confessed In July 1990, another elderly woman was to all three crimes. brutally raped and murdered in her home. Three months later, a third elderly woman Mark Nelson, special agent in charge of was raped and stabbed to death. Her hus- the North Carolina State Crime Laboratory, band was also murdered. Their house said, “Even though these terrible crimes was burned in an attempt to cover up the occurred more than 10 years ago, we crime, but fire/rescue personnel pulled never gave up hope of solving them one the bodies from the house before it was day.” engulfed in flames. Every law enforcement department When DNA analysis was conducted on throughout the country has unsolved biological evidence collected from vaginal cases that could be solved through recent swabs from each victim, authorities con- advancements in DNA technology. Today, cluded that the same perpetrator had investigators who understand which evi- committed all three crimes. However, dence may yield a DNA profile can identify there was no suspect. a suspect in ways previously seen only on television. Evidence invisible to the naked For 10 years, both the Goldsboro Police eye can be the key to solving a residential Department and the crime laboratory burglary, sexual assault, or murder. The refused to forget about these cases. With saliva on the stamp of a stalker’s threaten- funding from the National Institute of ing letter, the perspiration on a rapist’s Justice, the crime laboratory retested the mask, or the skin cells shed on the liga- biological evidence in all three cases with ture of a strangled child may hold the key newer DNA technology and entered the to solving a crime. DNA profiles into North Carolina’s DNA database. This would allow the DNA pro- In Austin, Texas, for example, an investi- file developed from the crime scene evi- gator knowledgeable about DNA technolo- dence to be compared to thousands of gy was able to solve the rape of a local convicted offender profiles already in the college student. Having read about the database. potential for obtaining DNA evidence from the ligature used to strangle a victim, the In April 2001, a “cold hit” was made to investigator requested DNA testing on the the perpetrator’s convicted offender DNA phone cord used to choke the victim in his profile in the database. The perpetrator case. He realized that in the course of

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choking someone, enough force and fric- Although DNA is not the only forensic tool tion is applied to the rope or cord that the available for the investigation of unsolved perpetrator’s skins cells may rub off his cases, advancements in DNA testing and hands and be left on the ligature. the success of DNA database systems have inspired law enforcement agencies The investigator’s request paid off in an throughout the country to reevaluate unanticipated way. In spite of the attack- cases previously thought unsolvable. The er’s attempt to avoid identification through purpose of this report is to provide law DNA evidence by wearing both a condom enforcement with a practical resource for and rubber gloves, a reliable DNA profile the review of old, cold, or unsolved cases was developed from the evidence. During that may be solved through DNA technolo- the struggle, the attacker was forced to gy and DNA databases. “The Long and use one hand to hold the victim down, Short of DNA” and “How Can DNA leaving only one hand to pull the phone Databases Aid Investigations?” will edu- cord tight. The attacker had to grab the cate the reader about the science and remaining end of the cord with his mouth, technology of DNA testing and DNA data- The successful thereby depositing his saliva on the cord. bases. “Practical Considerations” provides Although the developed profile came from important background information on legal review and saliva rather than skin, DNA not only and practical considerations regarding the investigation of solved the case in Austin, but also linked application of DNA technology to old, cold, the perpetrator to a similar sexual assault or unsolved cases. Finally, a step-by-step unsolved cases in Waco. process is provided to help investigators require coopera- select cases that would most likely be Without the investigator’s understanding solved with DNA evidence. As investigation among law of DNA technology and where DNA might tors advance through this process, they be found, the case may have gone enforcement, the should also keep in mind the array of unsolved. The successful review and other technology advancements, such as crime laboratory, investigation of unsolved cases require improved ballistics and fingerprint databas- the same basic elements as the investiga- es, that may benefit their investigation. and the prosecution of new cases: cooperation among law tor’s office. enforcement, the crime laboratory, and the prosecutor’s office. Investigators should be aware of technological Advancements in advances in DNA testing that may yield DNA technology profiles where previous testing was not Advancements in DNA analysis, together performed or was unsuccessful. The with computer technology and the crime laboratory can be essential to the Combined DNA Index System (CODIS),1 preliminary review of unsolved cases, for have created a powerful crimefighting tool example, by providing investigators with for law enforcement. CODIS is a comput- laboratory reports from previous testing er network that connects forensic DNA and consultation regarding the investiga- laboratories at the local, State, and nation- tive value of new DNA analysis techniques al levels. DNA database systems that use and DNA database search capabilities. CODIS contain two main criminal indexes Additionally, the prosecutor’s office should and a missing persons index. When a be involved as soon as a case is reopened DNA profile is developed from crime so that legal issues are addressed appro- scene evidence and entered into the priately. It is also extremely important that forensic (crime scene) index of CODIS, case reconstruction considers the victim the database software searches thou- or victim’s family and the importance of sands of convicted offender DNA profiles finality to closing a case.

2 USING DNA TO SOLVE COLD CASES

(contained in the offender index) of individ- in unsolved cases by covering the basics The power of a uals convicted of offenses such as rape of DNA analysis and its application to and murder. Similar to the Automated forensic casework. The report will also DNA database Fingerprint Identification System (AFIS), demonstrate how DNA database systems, system is evident CODIS can aid investigations by efficiently advancing technology, and cooperative comparing a DNA profile generated from efforts can enhance unsolved case inves- not only in the biological evidence left at a crime scene tigative techniques. success of against convicted offender DNA profiles and forensic evidence from other cases solving crimes contained in CODIS. CODIS can also aid New laws previously thought investigations by searching the missing persons index, which contains DNA pro- Advancements in DNA technology have unsolvable, but files of unidentified remains and DNA pro- led to significant changes in many States’ through the files of relatives of those who are missing. statutes, which may affect the manner in Because of the recidivistic nature of vio- which unsolved cases are investigated, prevention lent offenders, the power of a DNA data- filed, and prosecuted. Advancements in of crime. base system is evident not only in the the technology have been so significant success of solving crimes previously that laws are being created, amended, and thought unsolvable, but perhaps more even repealed to take advantage of its importantly, through the prevention of ability to identify and convict the guilty and crime. exonerate the innocent. Laws regarding DNA admissibility in court, its use in post- When properly documented, collected, and conviction appeals, the creation and stored, biological evidence can be analyzed expansion of databases, and the extension to produce a reliable DNA profile years, or elimination of statutes of limitation are even decades, after it is collected. Just as examples of the quickly evolving impact of evidence collected from a crime that DNA on the criminal justice system. Given occurred yesterday can be analyzed for the legal changes occurring throughout DNA, today evidence from an old rape kit, the country, constant contact and consul- bloody shirt, or stained bedclothes may tation with the local prosecutor is critical contain a valuable DNA profile. These new not only for the investigation of older analysis techniques, in combination with an cases but for all cases in which DNA may evolving database system, make a powerful be relevant evidence. argument for the reevaluation of unsolved crimes for potential DNA evidence. Statutes of limitation Knowledgeable law enforcement officers Statutes of limitation may be one of the are taking advantage of powerful DNA most difficult issues to overcome when analysis techniques by investigating crime examining older cases. Statutes of limita- scenes with a keener eye toward biologi- tion establish time limits under which cal evidence. The same new approach criminal charges can be filed for a particu- being applied to crime scene processing lar offense. These statutes are rooted in and current case investigation can be the protection of individuals from the use applied to older unsolved cases. Law of evidence that becomes less reliable enforcement agencies across the country over time. For example, witnesses’ mem- are establishing cold-case squads to sys- ories fade as time goes by. However, tematically review old cases for DNA and although some evidence, such as eyewit- other new leads. This report will serve as ness accounts, can lose credibility over a resource to assist law enforcement with time, DNA evidence has the power to maximizing the potential of DNA evidence determine truth 10, 15, even 20 years

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The reliability of after an offense is committed. States are all convicted felons to submit a DNA pro- beginning to realize that the reliability of file to the State database. The tendency DNA technology DNA technology may necessitate the for States to include all convicted felons in may necessitate reevaluation of statutes of limitation in the their databases dramatically increases the filing of cases. number of convicted offender DNA pro- the reevaluation files against which forensic DNA evidence of statutes Database expansion can be compared, thus making the database system a more powerful tool for law of limitation. The use of DNA evidence and convicted enforcement. offender DNA databases has expanded significantly since the first U.S. DNA data- New legal approaches base was created in 1989. Although State and local DNA databases established in DNA technology and DNA databases have the early 1990s contained only DNA pro- encouraged the development of new files from convicted murderers and sex approaches to old cases. One such offenders, the undeniable success of DNA approach is the filing of charges by “John databases has resulted in a national trend Doe” warrant. These warrants are based toward database expansion. All States on the unique DNA profile obtained from require at least some convicted offenders the analysis of unsolved crime scene evi- to provide a DNA sample to be collected dence. Although John Doe warrants are for DNA profiling and, in 2000, the Federal traditionally filed based on the physical Government began requiring certain description or alias of an unnamed sus- offenders convicted of Federal or military pect, investigators and prosecutors are crimes to also provide a DNA sample for now filing charges using the suspect’s the criminal DNA database. Recognizing DNA profile as the identifier. This innova- that the effectiveness of the DNA data- tive approach has allowed charges to be base relies on the volume of data con- filed that toll and permit old cases to be tained in both the forensic index (crime prosecuted when the person matching the scene samples) and the convicted offend- John Doe DNA profile is identified. John er index of CODIS, many States are Doe DNA warrants are one way to permit changing their database statutes to cases to remain active, allowing them the include less violent criminals. Many chance to be solved through the DNA States are enacting legislation to require database in the future.

4 The Long and Short of DNA

DNA is the fundamental building block for standard, it can be determined that it did an individual’s entire genetic makeup. It is not come from that known individual. a component of virtually every cell in the human body, and a person’s DNA is the same in every cell. That is, the DNA in a DNA technology person’s blood is the same as the DNA in his skin cells, saliva, and other biological advancements material. Recent advancements in DNA technology have improved law enforcement’s ability DNA analysis is a powerful tool because to use DNA to solve old cases. Original each person’s DNA is unique (with the forensic applications of DNA analysis were exception of identical twins). Therefore, developed using a technology called DNA evidence collected from a crime restriction fragment length polymorphism scene can implicate or eliminate a sus- (RFLP). Although very old cases (more pect, similar to the use of fingerprints. It than 10 years) may not have had RFLP also can analyze unidentified remains analysis done, this kind of DNA testing through comparisons with DNA from rela- may have been attempted on more recent tives. Additionally, when evidence from unsolved cases. However, because RFLP one crime scene is compared with evi- analysis required a relatively large quantity dence from another using CODIS, those of DNA, testing may not have been suc- crime scenes can be linked to the same cessful. Similarly, biological evidence perpetrator locally, statewide, and deemed insufficient in size for testing may nationally. not have been previously submitted for testing. Also, if a biological sample was If biological DNA is also a powerful tool because when degraded by environmental factors such biological evidence from crime scenes is evidence is as dirt or mold, RFLP analysis may have collected and stored properly, forensically been unsuccessful at yielding a result. available for valuable DNA can be found on evidence Newer technologies could now be suc- that may be decades old. Therefore, old cessful in obtaining results. testing or cases that were previously thought unsolv- retesting in able may contain valuable DNA evidence Newer DNA analysis techniques enable capable of identifying the perpetrator. unsolved case laboratories to develop profiles from biological evidence invisible to the naked eye, investigations, it such as skin cells left on ligatures or is important that Similar to fingerprints weapons. Unsolved cases should be eval- uated by investigating both traditional and DNA is often compared with fingerprints law enforcement nontraditional sources of DNA. Valuable in the way matches are determined. DNA evidence might be available that pre- and the crime When using either DNA or fingerprints to viously went undetected in the original identify a suspect, the evidence collected laboratory work investigation. from the crime scene is compared with a together to “known” standard. If identifying features If biological evidence is available for test- review evidence. are the same, the DNA or fingerprint can ing or retesting in unsolved case investiga- be determined to be a match. However, if tions, it is important that law enforcement identifying features of the DNA profile or and the crime laboratory work together fingerprint are different from the known to review evidence. Logistical issues

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Fingerprints DNA Strands regarding access to and the cost of DNA the STR regions that are analyzed for analysis will be a factor, as well as issues forensic testing intensifies the discrimina- that relate to the discriminating power of tion between one DNA profile and anoth- each technology and that might affect the er. For example, the likelihood that any outcome of the results. Laboratory per- two individuals (except identical twins) will sonnel can also provide a valuable per- have the same 13-loci DNA profile can be spective on which evidence might yield as high as 1 in 1 billion or greater. The valuable and probative DNA results. Federal Bureau of Investigation (FBI) has Finally, if previously tested biological evi- chosen 13 specific STR loci to serve as dence produced a DNA profile but exclud- the standard for CODIS. The purpose of ed the original suspect, revisiting those establishing a core set of STR loci is to “exclusion” cases in the context of com- ensure that all forensic laboratories can paring them with DNA databases might establish uniform DNA databases and, prove to be very valuable to solving old more importantly, share valuable forensic cases. information. If the forensic or convicted offender CODIS index is to be used in the PCR analysis investigative stages of unsolved cases, DNA profiles must be generated by using PCR (polymerase chain reaction) enhances STR technology and the specific 13 core DNA analysis and has enabled laboratories STR loci selected by the FBI. to develop DNA profiles from extremely small samples of biological evidence. The Mitochondrial DNA analysis PCR technique replicates exact copies of DNA contained in a biological evidence Mitochondrial DNA (mtDNA) analysis If the convicted sample without affecting the original, allows forensic laboratories to develop much like a copy machine. RFLP analysis DNA profiles from evidence that may not offender or requires a biological sample about the size be suitable for RFLP or STR analysis. forensic index of a quarter, but PCR can be used to While RFLP and PCR techniques analyze reproduce millions of copies of the DNA DNA extracted from the nucleus of a cell, of CODIS is to contained in a few skin cells. Since PCR mtDNA technology analyzes DNA found in be used in the analysis requires only a minute quantity of a different part of the cell, the mitochon- DNA, it can enable the laboratory to ana- drion (see exhibit 1). Old remains and evi- investigative lyze highly degraded evidence for DNA. dence lacking nucleated cells—such as stages of an On the other hand, because the sensitive hair shafts, bones, and teeth—that are PCR technique replicates any and all of unamenable to STR and RFLP testing may unsolved case, the DNA contained in an evidence sample, yield results if mtDNA analysis is per- DNA profiles must greater attention to contamination issues formed. For this reason, mtDNA testing is necessary when identifying, collecting, can be very valuable to the investigation of be generated and preserving DNA evidence. These fac- an unsolved case. For example, a cold using STR tors may be particularly important in the case log may show that biological evi- evaluation of unsolved cases in which evidence in the form of blood, semen, and analysis. dence might have been improperly collect- hair was collected in a particular case, but ed or stored. that all were improperly stored for a long period of time. Although PCR analysis STR analysis sometimes enables the crime laboratory to generate a DNA profile from very Short tandem repeat (STR) technology is a degraded evidence, it is possible that the forensic analysis that evaluates specific blood and semen would be so highly regions (loci) that are found on nuclear degraded that nuclear DNA analysis would DNA. The variable (polymorphic) nature of not yield a DNA profile. However, the hair

6 USING DNA TO SOLVE COLD CASES

shaft could be subjected to mtDNA analy- Y-chromosome analysis sis and thus be the key to solving the case. Finally, it is important to note that all Several genetic markers have been iden- maternal relatives (for example, a person’s tified on the Y chromosome that can mother or maternal grandmother) have be used in forensic applications. Y- identical mtDNA. This enables unidentified chromosome markers target only the remains to be analyzed and compared to male fraction of a biological sample. the mtDNA profile of any maternal relative Therefore, this technique can be very for the purpose of aiding missing persons valuable if the laboratory detects complex or unidentified remains investigations. mixtures (multiple male contributors) with- Although mtDNA analysis can be very in a biological evidence sample. Because valuable to the investigation of criminal the Y chromosome is transmitted directly cases, laboratory personnel should always from a father to all of his sons, it can also be involved in the process. be used to trace family relationships among males. Advancements in Y-chromosome testing may eventually eliminate the need for laboratories to extract and sepa- Exhibit 1. Cell diagram rate semen and vaginal cells (for example, from a vaginal swab of a rape kit) prior to analysis.

Mitochondrion Cooperative efforts with the crime laboratory are essential to deciding which analysis methods will be most valuable in a Nucleus particular case. It is important to note, however, that while RFLP and mtDNA test- Chromosomes ing may be valuable to the investigation of an old case, current DNA databases are being populated with DNA profiles that are generated using STR analysis. RFLP and mtDNA profiles are not compatible with the convicted offender or forensic indexes of CODIS.2

7 How Can DNA Databases Aid Investigations?

The development and expansion of data- may be linked to each other, thereby aid- bases that contain DNA profiles at the ing an investigation, which may eventually local, State, and national levels have great- lead to the identification of a suspect. ly enhanced law enforcement’s ability to solve cold cases with DNA. Convicted offender databases store hundreds of What is CODIS? thousands of potential suspect DNA profiles, against which DNA profiles CODIS is a computer software program developed from crime scene evidence that operates local, State, and national can be compared. databases of DNA profiles from convicted offenders, unsolved crime scene evidence, and missing persons. Every State in the Nation has a statutory provision for SUCCESS STORY the establishment of a DNA database that A “forensic hit” occurred in the National DNA Index System (NDIS) that linked allows for the collection of DNA profiles a dead Florida man’s DNA profile to eight serial unsolved rapes in Washington, from offenders convicted of particular D.C. and three offenses in Florida. crimes. CODIS software enables State, local, and national law enforcement crime In 1999, Leon Dundas was killed in a drug deal. Investigators remembered laboratories to compare DNA profiles elec- Dundas refusing to give a blood sample in connection with a rape investigation tronically, thereby linking serial crimes to in 1998. They were able to obtain Dundas’ blood sample through the medical each other and identifying suspects by examiner’s office and forwarded it to the DNA lab at the Florida Department of matching DNA profiles from crime scenes Law Enforcement. Dundas’ DNA profile was compared with the national foren- with profiles from convicted offenders. sic index and a match was made between Dundas and DNA evidence from a The success of CODIS is demonstrated by rape victim in Washington, D.C. the thousands of matches that have linked serial cases to each other and cases that The FBI then entered DNA evidence from additional unsolved rapes committed have been solved by matching crime in Washington. Dundas’ DNA matched seven additional rapes in Washington scene evidence to known convicted and three more in Jacksonville, Florida. Police in Washington said that without offenders. DNA, they would have never identified Dundas, who had no prior recorded his- tory of violent crime. The missing persons index consists of the unidentified persons index and the refer- Given the recidivistic nature of many ence index. The unidentified persons crimes, such as sexual assault and bur- index contains DNA profiles from recov- glary, a likelihood exists that the individual ered remains, such as bone, teeth, or hair. who committed the crime being investi- The reference index contains DNA profiles gated was convicted of a similar crime and from related individuals of missing per- already has his or her DNA profile in a sons so that they can be periodically com- DNA database that can be searched by pared to the unidentified persons index. CODIS. Moreover, CODIS also permits the All samples for this index are typed using cross-comparison of DNA profiles devel- mtDNA and STR DNA analysis (if possible) oped from biological evidence found at to maximize the power of advancing crime scenes. Even if a perpetrator is not technology. identified through the database, crimes

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How does CODIS work? A description of the three CODIS tiers follows (see exhibit 2). CODIS uses two indexes to generate investigative leads in crimes for which bio- ■ Local. Typically, the Local DNA Index logical evidence is recovered from a crime System (LDIS) installed at crime labora- scene. The convicted offender index con- tories is operated by police departments tains DNA profiles of individuals convicted or sheriffs’ offices. DNA profiles origi- of certain crimes ranging from certain nated at the local level can be transmit- misdemeanors to sexual assault and mur- ted to the State and national levels. The offender der. Each State has different “qualifying offenses” for which persons convicted of ■ State. Each State has a designated labo- index contains them must submit a biological sample for ratory that operates the State DNA DNA profiles inclusion in the DNA database. The foren- Index System (SDIS). SDIS allows local sic index contains DNA profiles obtained laboratories within that State to com- of individuals from crime scene evidence, such as pare DNA profiles. SDIS also is the com- convicted of semen, saliva, or blood. CODIS uses munication path between the local and computer software to automatically national tiers. SDIS is typically operated certain crimes. search across these indexes for a poten- by the agency responsible for imple- The forensic index tial match. menting and monitoring compliance with the State’s convicted offender contains DNA A match made between profiles in the statute. profiles obtained forensic index can link crime scenes to each other, possibly identifying serial ■ National. The National DNA Index from crime offenders. Based on these “forensic hits,” System (NDIS) is the highest level of scene evidence. police in multiple jurisdictions or States the CODIS hierarchy and enables quali- can coordinate their respective investiga- fied State laboratories that are actively tions and share leads they have developed participating in CODIS to compare independent of each other. Matches made DNA profiles. NDIS is maintained by between the forensic and convicted the FBI under the authority of the DNA offender indexes can provide investigators Identification Act of 1994. with the identity of a suspect(s). It is important to note that if an “offender hit” is obtained, that information typically is Limitations of using the used as probable cause to obtain a new DNA sample from that suspect so the DNA database match can be confirmed by the crime lab- The more data contained in the forensic oratory before an arrest is made. and offender indexes of CODIS, the more powerful a tool it becomes for law LDIS, SDIS, and NDIS enforcement, especially in its application to unsolved case investigation. However, CODIS is implemented as a distributed because many jurisdictions are in the database with three hierarchical levels (or process of developing and populating their tiers)—local, State, and national. All three DNA databases, convicted offender and levels contain forensic and convicted forensic casework backlogs have been offender indexes and a population file created over time and continue to grow (used to generate statistics). The hierarchi- for several reasons. First, as States recog- cal design provides State and local labora- nize the crime-solving potential of DNA tories with the flexibility to configure databases, they continue to expand CODIS to meet their specific legislative the scope of their convicted offender and technical needs. legislation, which increases the number of

10 USING DNA TO SOLVE COLD CASES

Exhibit 2. CODIS tiers

samples to be collected and analyzed by that have been collected but have not yet the DNA laboratory. As a result, more than been analyzed. Although Federal funding 1 million uncollected convicted offender has played an important role in reducing DNA profiles are “owed” to the system. existing backlogs, the crimefighting potential of DNA has prompted many States to An equally important but more difficult revise their statutes to require nonviolent problem to quantify is that of unprocessed convicted offenders to provide a DNA casework that contains biological evi- sample for analysis and upload into dence. This casework backlog may include CODIS. The trend toward expanding con- nonsuspect or unsolved cases that could victed offender DNA statutes to include be analyzed and solved as a result of nonviolent offenders has significantly advancements in DNA technology. increased the number of DNA samples requiring collection and analysis. Although Convicted offender backlogs the success of using the DNA database as a crime-solving and crime-prevention tool Although all 50 States have passed DNA can easily be demonstrated once convict- database legislation, many States have ed offender backlogs are reduced, it backlogs of convicted offender samples should be recognized that new backlogs

11 SPECIAL REPORT / JULY 02

are instantly created by the passage of biological evidence are not being analyzed expanded DNA legislation laws. Convicted and entered into the DNA database. In offender backlogs are an ongoing logistical many jurisdictions, DNA from crime issue that can compound the complexity scenes is still primarily used to prosecute of investigating cold cases by using the offenders, not to investigate crimes. The DNA database. convicted offender backlog and limited resources for casework going to trial pre- Forensic casework backlogs clude State forensic laboratories from analyzing all biological evidence for DNA, Addressing issues that affect the efficient which in turn prevents law enforcement and effective use of DNA databases in the from being able to realize the full crime- United States is complicated further by solving potential of CODIS. the existence of casework backlogs. This refers to biological evidence in perhaps The backlog of forensic cases has practical tens of thousands of criminal cases, consequences for most law enforcement including violent and nonviolent crimes, agencies in the United States. Laboratory that has not been tested or retested for capacity limitations result in the ability to DNA. process crime scene samples from only the most serious of offenses. More and Unprocessed rape kits are a clear example more, however, agencies such as those in of this kind of backlog. Despite the estab- the United Kingdom are discovering the lished fact that rape typically yields biologi- value of DNA technology in solving proper- cal evidence, as of October 1999, at least ty crimes. Blood left on a broken apart- 180,000 rape kits remained on shelves ment window or saliva found on a across the country, unprocessed, because discarded beer bottle can be used to no suspects have been identified. The identify burglars, and the skin cells rubbed DNA evidence from these and other cri- off onto the steering wheel of a stolen minal cases often is not analyzed and vehicle can solve car thefts. However, as entered into the DNA database because long as forensic laboratories remain able forensic laboratories have to prioritize their to process only the most serious cases, work and cases scheduled for trial take the full potential of DNA technology to precedence over cases in which no sus- solve crime will remain untapped. pect is known. In most jurisdictions, nonsuspect criminal cases that contain

12 Practical Considerations

A broad range of considerations must be shut as the past form of “sealing.” made long before any DNA testing is actu- Multiple items may be sealed in one plas- ally attempted in older, unsolved cases. tic bag, or even unpackaged in large, These include— open, cardboard boxes. Unprotected microscope slides from medical facilities ■ Legal considerations, such as the applica- might also be found as a result of investi- Local prosecutors tion or expiration of statutes of limitation. gating old cases. No attempt should be made on the part of the investigator to can provide ■ Technological considerations, such as separate and repackage evidence. The valuable insight the nature and condition of the evidence condition and position that the evidence into legal issues. as originally collected, stored, and in has been stored in could provide valuable some instances, subjected to other clues to the forensic scientist for testabili- Victim/witness forensic tests. ty of evidence. Only when evidence is found unpackaged should the investigator units or advocates ■ Practical considerations, such as the properly package and label the item(s) to availability of witnesses in the event can help locate, minimize the possibility for contamination DNA testing would identify a suspect from that point forward. It is important educate, and and lead to an arrest and a trial. that any evidence items are handled mini- encourage ■ Resource issues, such as the time and mally and only by individuals wearing dis- witnesses. Con- money available for investigation and posable gloves. As always, it is also very forensic analysis. important that all actions taken as a result sultation with of opening, evaluating, packaging, or representatives The nature and scope of these issues repackaging evidence are documented require that any approach to reexamining thoroughly in the case folder. from the crime old cases for potential DNA evidence be laboratory is collaborative, whether by an individual Degraded evidence investigator or by a specialized unit devel- critical. oped specifically for cold case review. Prior to the frequent use of DNA technolo- Local prosecutors can provide valuable gy, biological evidence may have been insight into legal issues that might prevent collected and stored in ways that were not or help a future prosecution. Victim/witness necessarily the best methods for preserv- units or advocates can provide valuable ing samples for future DNA testing. For assistance with locating, educating, and example, evidence containing biological encouraging witnesses. Consultation with fluids that were originally collected for representatives from the crime laboratory ABO Blood Typing analysis or other serolo- is critical to ensuring that potential DNA gy methods may have been packaged or evidence can be successfully analyzed. stored in ways that can limit DNA testing. Some methods of collection and storage may promote the growth of bacteria and Evidence considerations mold on the evidence. Bacteria can seri- ously damage or degrade DNA contained When collecting unsolved case evidence in biological material and inhibit the ability from storage facilities, the case investiga- to develop a DNA profile; however, evi- tor should be ready to handle all types of dence can still sometimes yield DNA packaging disasters. Evidence may be results. For example, PCR technology can stored in heavy-duty plastic bags, stapled allow the laboratory to develop profiles

13 SPECIAL REPORT / JULY 02

from some moldy biological samples, It is also important to avoid contamination whereas other evidence may fail to yield a when handling biological evidence during usable DNA profile, even when no mold is the course of the current review. If evi- visible. Therefore, close consultation with dence that may contain biological material the laboratory is important to determine is already sealed, do not reopen it before the type of DNA testing most likely to sending it to the laboratory. (See Evidence yield results on the available evidence. Handling Recommendations.)

Contamination issues Legal considerations Because of the particularly sensitive nature of DNA technology, the potential Numerous legal issues might arise when contamination of evidence should be care- examining older cases for potential DNA fully considered. Technologies used to evidence. These issues are most likely analyze evidence prior to the forensic jurisdictionally specific and may differ from application of DNA were not always sensi- State to State. Although most jurisdictions tive to contaminants. Evidence in older maintain no statute of limitation for filing cases may have been collected in ways charges in a homicide case, States can that lacked appropriate contamination or vary widely in the time allowed for filing cross-contamination safeguards, which charges in other cases, such as rape and can make the DNA results less useful or other sexual assault crimes. Furthermore, even misleading. In these cases, clarifying in recognition of DNA technology’s ability results by identifying the contributor of an to solve old cases, many States are additional profile can determine whether extending or even eliminating statutes the DNA results may now be used. When of limitation for certain crimes. a mixture is detected, a careful reconstruction of the evidence collection, stor- Chain of custody age, and analysis process must be undertaken. It may be determined that When a case remains unsolved for a long DNA profiles will be required from on- period of time, evidence is usually handled scene officers, evidence technicians, or by an increased number of individuals. laboratory scientists who had access to Many unsolved cases to be reviewed for the evidence for comparison with evi- DNA evidence may have been previously dence results. In these instances, proper reinvestigated or handled by several differ- chain-of-custody reconstruction is critical. ent investigators as a result of new leads or periodic, systematic reviews. Further- more, as cases age, the likelihood increas- EVIDENCE HANDLING RECOMMENDATIONS es that evidence may be moved to new or remote storage locations as evidence ■ Wear gloves. Change them between handling each item of evidence. from newer cases fills police department ■ Use disposable instruments or clean instruments thoroughly before and shelves. after handling each evidence sample. Many cases may also have had evidence ■ Avoid touching the area where you believe DNA may exist. submitted to the laboratory for various ■ Avoid touching your face, nose, and mouth when examining and repackaging forms of forensic testing. Evidence in evidence. older cases may have been submitted for ■ Put dry evidence into new paper bags or envelopes; do not use plastic bags. standard serological testing, but can now ■ Do not use staples. be tested for DNA with much greater success. Hair previously submitted for stan- ■ If repackaging of evidence is necessary, consult with laboratory personnel. dard microscopic hair analysis may now

14 USING DNA TO SOLVE COLD CASES

be submitted for mtDNA testing. As with for up to 7 years after the commission of It should not be all criminal investigations, chain-of-custody the crime. Exceptions also exist for cases issues are critical to maintaining the in which child victims are assaulted by a assumed that integrity of the evidence. In all cases, the family member, which can be valuable in victims and wit- ultimate ability to use DNA evidence will the context of a current investigation. depend on the ability to prove that the nesses are still chain of custody was maintained. interested in pur- Victim and witness suing the case. Statutes of limitation considerations Whenever pos- One of the first issues to address when Another important consideration to be reviewing an unsolved case is whether made early in the process is the willing- sible, enlist the the statutes of limitation on a case have ness of victims and witnesses to proceed. aid of victim run out. Several considerations arise when Although many victims may continuously addressing a statute of limitation issue. monitor the progress of their investiga- service providers. Good communication between law en- tions, some choose to detach from the forcement and local prosecutors is critical process over time. Reinvestigating a case when examining these legal questions. may cause renewed psychological trauma to the victim and victim’s family. It should Changes in statutes. Advances in DNA not be assumed that victims and witness- technology and the creation of DNA data- es, even if they were eager to pursue the bases are leading many criminal justice case when it occurred, are still interested professionals to rethink time limits placed in pursuing the case. A phone call from an on the filing of criminal charges. Because investigator years later may not be a wel- biological evidence can yield reliable DNA come event. Whenever possible, enlist analysis results years after the commis- the aid of victim service providers. If a sion of a crime, many State legislatures new officer is handling the investigation, have begun to extend, and in some enlisting the assistance of the original cases eliminate, the statutes of limitation investigator to make the first contact with for some crimes and in certain circum- the victim may also be helpful. stances. Many States have extended the length of time for which a complaint can The older a case is, the more difficult it be filed, other States have eliminated may be to locate witnesses. However, statutes of limitation for certain crimes, early identification of victim and witness and some legislation is retroactive. availability may ultimately save significant resources. Consultation with prosecutors Exceptions to statutes. Exceptions often is mandatory when considering whether a exist under existing and new statutes. witness would be necessary at trial. Under such exceptions, time can be added to the statute of limitation, giving police the legal authority to arrest even if it appears as though the statute has run STATUTE OF LIMITATION RECOMMENDATIONS out. For example, many jurisdictions have ■ exceptions for a suspect’s flight from juris- Know the original statute of limitation. diction. In a case for which there is a ■ Determine whether the law has changed regarding time limits for filing. 5-year statute of limitation, if the govern- If so, is the law retroactive? ment can prove that the suspect has been ■ Determine whether there are exceptions to the statute. absent from the jurisdiction for 2 years, ■ Consult with the prosecutor. the State can still file against the suspect

15 Identifying, Analyzing, and Prioritizing Cases

Good Whether the process of reviewing from years ago. In some departments a unsolved cases is initiated by a single offi- formalized cold-case unit may systemati- communication cer or by a specialized unit, it must ulti- cally review cases for the potential of DNA between police, mately be a team effort. At all stages of testing. Other cases may be identified by the process, investigators should avail coordinated, interdepartmental efforts, vic- laboratories, and themselves of the scientific advice of the tims or witnesses who have heard about prosecutors can laboratory and the legal expertise of the the potential of DNA evidence, and labora- local prosecutor’s office. Close consulta- tories taking inventory of their storage help identify and tion with the laboratory can ensure that facilities. If a department is pursuing a sys- convict serious evidence integrity is maintained and that tematic review of cases, either by one or limited laboratory resources are allocated two officers or by a formal unit, there are offenders and save effectively. Similarly, prosecutors can help many sources that can be consulted for valuable time identify issues that might occur at trial if a valuable investigative information, such suspect is identified and arrested upon as— and resources. successful DNA testing. Good communication between police, laboratories, and ■ Autopsy, laboratory, prosecutor, and prosecutors can help identify and convict local agency logbooks. serious offenders and save valuable time ■ and resources. Retired investigators. ■ Computer databases. Identify potential cases Identify statute of for review limitation issues An initial step in the DNA review of Statute of limitation issues might affect unsolved cases is to identify cases that the ultimate ability to prosecute a case. might be amenable to DNA testing. While Cases should be preliminarily reviewed by the cases considered for this kind of investigators in conjunction with the pros- review will vary from jurisdiction to juris- ecutor’s office to identify which prosecu- diction, it is important to define minimum tions would be barred by the statutes of requirements that will likely benefit from limitation. If the goal of the unsolved case this approach. Issues such as statutes of review program is to obtain convictions limitation and solvability factors should be and statutes of limitation have expired on thoroughly examined in cooperation with a a particular case, a department may wish prosecutor and the forensic laboratory to to save its resources for cases likely to establish guidelines for case selection. It yield convictions. However, if the goal also will be important to identify the ulti- of the program is to solve and close un- mate goals of the program so that the solved cases regardless of whether a con- selection criteria can be tailored to meet viction could be obtained, a jurisdiction those specific goals. may decide to review all cases that qualify under its guidelines. This is an important Cases that could benefit from a review consideration in the context of investigat- for potential DNA evidence can be identi- ing serial offenders whose criminal acts fied from numerous sources. In some might span the course of years or instances a single police officer or investi- decades. gator may remember an unsolved case

17 SPECIAL REPORT / JULY 02

Define categories of cases— ■ How many qualifying cases are there? solvability factors ■ Where are the case files located? Because the number of cases that qualify for reinvestigation might be very large, it ■ Are case summaries available? may be beneficial for a jurisdiction to define cases according to several solvabili- ■ How many cases will be assigned to ty factors. Solvability factors include facts an investigator? and circumstances of a case that influence the likelihood that it might be solved To establish an investigative hierarchy, through advancements in DNA technolo- qualifying cases should be reviewed by gy. For example, a high probability exists experienced, proficient investigators. A that analysis of nonsuspect rape kits will checklist can be used throughout the yield valuable DNA results. Profiles gener- review process so that managers can ated as a result of DNA analysis can now decide which cases will be worked first. be entered into CODIS, which can solve a A checklist can also provide review pro- case by matching to a convicted offender, cess consistency throughout the agency. or aid investigations by linking serial rapes (See Sample Checklist at the end of this to each other. Additionally, if an unsolved report.) The following categories may murder case contains biological evidence serve as a model for a hierarchy in priori- foreign to the victim that did not produce tizing cases: viable results from ABO blood typing or ■ There is a known suspect and physical RFLP DNA analysis, evidence could be evidence appears to have been pre- reanalyzed with the more discriminating served in a manner consistent with suc- and powerful STR technology. It is also cessful DNA testing and use of CODIS. important to recognize and sort out cases that might not be as likely to be solved ■ There is no known suspect but physical with DNA technology. An example might evidence has been preserved in a man- be an unsolved drive-by homicide because ner consistent with successful DNA the perpetrator most likely would not have testing and use of CODIS. left biological evidence at this kind of crime scene. ■ There is no known suspect and evidence was collected and preserved in a manner that may make it difficult to Case review— obtain a DNA profile. establish priorities Once solvability factors and statute of limi- Locating case files, tation issues are addressed, it is important to continue the process by identifying the obtaining evidence logs, cases to be reviewed first. To preserve and other documentation investigative resources when considering Locating the case file and original evidence a larger number of unsolved cases for for the investigation may be a challenging review, jurisdictions may prioritize accord- endeavor. Changes in personnel, proce- ing to the likelihood that cases will be dure, and facilities and the passage of solved or the likelihood that investigations time may complicate the process. When will be aided. In establishing this priority, searching for a case file or evidence, an the following criteria can be considered: investigator may need to look in numerous

18 USING DNA TO SOLVE COLD CASES

places. Potential locations include, but are memorialize proper chain of custody. not limited to, the following: Cooperation with the crime laboratory is crucial to locate and interpret existing ■ Police department property rooms (case forensic reports and to determine whether files, evidence logs, whole evidence). evidence would be amenable to reanalysis with new DNA techniques. ■ Property warehouses (case files, evidence logs, whole evidence). Many combinations of options are available to investigators and laboratory per- ■ Public crime laboratories (previously sonnel if biological evidence was available tested/submitted evidence, lab reports). and previously tested. Exhibit 3 may serve to help investigators as they work with the ■ Private laboratories (previously tested laboratory to discuss options throughout evidence, lab reports). the course of the investigation. ■ Hospital/medical facilities (rape kits, medical reports, slides). Locate biological evidence

■ Coroner/medical examiners’ offices When reviewing the case file for potential (autopsy reports). DNA evidence, it is important to know what kinds of evidence may yield a DNA ■ Courthouse property rooms. profile. Given the power and sensitivity of newer DNA testing techniques, DNA can ■ Prosecutors’ offices (previous trial or be collected from virtually anywhere. Only suspect investigation). a few cells can be sufficient to obtain useful DNA information to help solve a case. ■ Retired investigators’ files (case notes Exhibit 4 identifies some common items of and details not contained in file). evidence that may have been collected previously but not analyzed for the presence ■ Other investigating agency offices of DNA evidence. Remember, if a stain is (investigative leads—serial offender). not visible it does not mean that there are not enough cells for DNA typing. Further, Forensic testing reports and DNA does more than just identify the previously tested evidence source of the sample; it can place a known individual at a crime scene, in a home, or in Because advancements in DNA technolo- a room where the suspect claimed not to gy enable laboratories to successfully ana- have been. It can refute a claim of self- lyze old evidence that might have been defense and put a weapon in the suspect’s improperly stored or subjected to previous forensic analysis, it will be very valuable to locate any and all forensic reports that were produced as a result of previous DNA CAN DO MORE . . . analysis and/or testing. ABO blood typing, . . . than identify a suspect. It can also— microscopic hair analysis, RFLP DNA ■ analysis, or fingerprint analysis (among Place a known individual at a crime scene. others) might have been performed in the ■ Refute a claim of self-defense. course of the original investigation. The ■ Put a weapon in a suspect’s hand. original case file should indicate whether and which types of forensic analysis were ■ Change a suspect’s story from an alibi to one of consent. attempted. These reports also serve to

19 SPECIAL REPORT / JULY 02

hand. It can also provide irrefutable evi- gation on cooperative efforts between the dence that can change a suspect’s story laboratory and prosecutor can save valu- from an alibi to one of consent. able resources, develop leads, and identify previously overlooked evidence that may yield a DNA profile. Evaluate for probative DNA evidence Continue investigative On completion of reviewing the case file, protocol reports, and evidence in consultation with the laboratory, it will be necessary to iden- If DNA analysis is to be conducted, it may tify which evidentiary items will be be important to obtain reference samples amenable to DNA analysis. Consultation from prior suspects, and it might be nec- with the laboratory will be essential to essary to be creative when obtaining determine the likelihood of obtaining these samples. While a biological sample results from DNA analysis, and consulta- in the form of blood or saliva can be tion with a prosecutor is very important to obtained voluntarily through a consent determine which evidence will be proba- form, a standard reference sample might tive to the case. Building the new investi- already exist if previous forensic analysis,

Exhibit 3. Investigative options

Test conducted Original results Original interpretation Options for investigators

RFLP/PCR Obtained profiles. No suspects identified. Is the original extract remaining? 1. If so, retest using STR technique and submit to CODIS. 2. If not, reextract the original sample using STR technique and submit to CODIS. RFLP Inconclusive or no results obtained. Sample size may have been Is the original extract remaining? insufficient or not concentrated 1. If so, retest using STR technique and enough. submit to CODIS. 2. If not, reextract the original sample using STR technique and submit to CODIS. PCR Inconclusive or result intensity Sample size may have been Is the original extract remaining? below “S” and “C” dots. insufficient. 1. If so, retest using STR technique and submit to CODIS. 2. If not, reextract the original sample using STR technique and submit to CODIS. Conventional serology (ABO, secretor Obtained a type in these systems. Poor statistics and no searching If original evidence still exists, extract status, enzymes such as EsD, PGM, capability. the sample using STR technique and GLO I, EAP, ADA, AK). submit to CODIS. None 1. Limited sample size. If original evidence still exists, extract 2. No suspects, did not process the sample using STR technique and further. submit to CODIS. 3. No request at the time of analysis.

20 USING DNA TO SOLVE COLD CASES

such as serological testing, was per- Follow agency procedures formed during the course of the original investigation. for submitting the DNA profile to CODIS Additionally, elimination samples from any- one who had lawful access to the crime On successful laboratory analysis resulting scene, such as family members, may be in a DNA profile developed from crime required if the laboratory determines that scene evidence, existing and/or new sus- there is more than one DNA profile pres- pect DNA profiles should be compared ent in the evidence sample. Early identi- with the evidence profile. If the laboratory fication of the location and status of determines a match between a suspect persons who might be requested to sub- and the evidence, the prosecutor’s office mit an elimination sample could save valu- should be consulted on how to proceed. able time and resources if the laboratory However, if a match is not found, agency needs such information. Consultation with procedures should be followed, in accor- the laboratory is essential to properly coor- dance with the crime laboratory, to submit dinating this process. the crime scene evidence DNA profile into CODIS.

Exhibit 4. Common items of evidence

Evidence Possible location of DNA on the evidence Source of DNA

Baseball bat Handle Skin cells, sweat, blood, tissue Hat, bandanna, or mask Inside surfaces Sweat, hair, skin cells, dandruff, saliva Eyeglasses Nose or ear piece, lens Sweat, skin cells Facial tissue, cotton swab Surface Mucus, blood, sweat, semen, ear wax Dirty laundry Surface Blood, sweat, semen, saliva Toothpick Surface Saliva Used cigarette Cigarette butt (filter area) Saliva Used stamp/envelope seal Moistened area Saliva Tape or ligature Inside or outside surface Skin cells, sweat, saliva Bottle, can, or glass Mouthpiece, rim, outer surface Saliva, sweat, skin cells Used condom Inside/outside surface Semen, vaginal or rectal cells Bed linens Surface Sweat, hair, semen, saliva, blood “Through and through” bullet Outside surface Blood, tissue Bite mark Surface of skin Saliva Fingernail/partial fingernail Scrapings Blood, sweat, tissue, skin cells

Note: When reviewing evidence, it is important to maintain chain of custody, consult with laboratory personnel, and take all appropriate precautions against contamination, including wearing gloves and changing them between handling of different pieces of evidence.

21 SPECIAL REPORT / JULY 02

Because CODIS contains hundreds of have statute of limitation issues that might thousands of convicted offender DNA pro- prevent the prosecution of the case if a files, it is possible that the person who match is not determined in a timely man- committed the unsolved crime being ner. Therefore, if no offender match investigated was convicted of a qualifying occurs in cases in which statutes of limita- offense that required submission of a tion are an issue, consideration may be DNA profile to the database. If that person given, in consultation with the prosecutor, has not previously been convicted of a to preparing a John Doe warrant. These qualifying offense, especially in light of types of warrants can identify the perpe- expanding database law, it is possible that trator according to his or her DNA profile. they will be convicted in the future. The 13-loci profile generated by the crime Further, because the forensic index of laboratory should be clearly printed on the CODIS contains thousands of crime scene face of the warrant. The John Doe warrant evidence profiles, the investigation could is not novel; however, the unconventional be aided if a match is made to another method of describing an individual by his forensic DNA profile already in the data- or her DNA profile may allow for pros- base. Finally, an investigator should not ecution of a case if a DNA match is assume that a new DNA profile generated determined in the course of future investi- from unsolved case evidence and submit- gations or as a result of the CODIS sys- ted to the laboratory for entry into CODIS tem being populated with more convicted will be compared with every possible con- offender and forensic DNA profiles. victed offender or crime scene index profile. The investigator may need to proactively request that his CODIS admin- Notes istrator search the new profile against the local, State, and national DNA databases. 1. CODIS uses two indexes—the forensic index and the offender index—to generate investigative leads in crimes where biological evidence is recovered from crime scenes. The forensic index contains DNA Prepare a John Doe warrant profiles of biological crime scene evidence and the offender index contains DNA profiles of individuals CODIS is a powerful crime-solving and convicted of a qualifying offense. crime-prevention tool, but many cases will 2. CODIS has a missing persons index that exclusive- not be solved as a result of entering a ly contains mtDNA profiles; the convicted offender DNA profile into the forensic index of the and forensic indexes of CODIS exclusively contain database. Additionally, many cases will STR DNA profiles.

22 USING DNA TO SOLVE COLD CASES

SAMPLE CHECKLIST

■ Identify potential cases. ■ Identify any statute of limitation issues (consult with prosecutors). ■ Define case categories according to solvability factors. ■ Prioritize cases (consider solvability factors). ■ Locate and review the case file; obtain evidence logs and other documentation such as laboratory and autopsy reports. ■ Locate previous forensic testing reports and location of previously tested evidence. For example— ■ Blood previously ABO typed. ■ Hair analyzed microscopically. ■ Fingerprint evidence. ■ Locate crime scene evidence containing biological material. ■ Evaluate the case and evidence for potential probative DNA. Be sure to— ■ Consider all evidentiary possibilities. ■ Take appropriate precautions against contamination. ■ In consultation with the laboratory and prosecutors, submit appropriate (probative) evidence to the laboratory for testing. ■ Continue investigative protocol. If needed, obtain reference samples from suspects— ■ Voluntarily using a consent form. ■ By using a previously obtained sample (e.g., if a reference sample was used for standard serological testing). ■ Identify witness issues— ■ Legal availability. ■ Willingness to proceed. ■ Location. ■ If a profile does not match suspect profiles, follow agency procedures for submitting the evidence profile to CODIS. ■ If no offender match occurs in cases in which statutes of limitation are an issue, prepare a John Doe warrant.

23 About the National Institute of Justice NIJ is the research, development, and evaluation agency of the U.S. Department of Justice and is solely dedicated to researching crime control and justice issues. NIJ provides objective, independent, nonpartisan, evidence-based knowledge and tools to meet the challenges of crime and justice, particularly at the State and local levels. NIJ’s principal authorities are derived from the Omnibus Crime Control and Safe Streets Act of 1968, as amended (42 U.S.C. §§ 3721–3722).

NIJ’s Mission In partnership with others, NIJ’s mission is to prevent and reduce crime, improve law enforcement To find out more about the National and the administration of justice, and promote public safety. By applying the disciplines of the Institute of Justice, please contact: social and physical sciences, NIJ— National Criminal Justice • Researches the nature and impact of crime and delinquency. Reference Service • Develops applied technologies, standards, and tools for criminal justice practitioners. P.O. Box 6000 • Evaluates existing programs and responses to crime. Rockville, MD 20849–6000 •Tests innovative concepts and program models in the field. 800–851–3420 • Assists policymakers, program partners, and justice agencies. e-mail: [email protected] • Disseminates knowledge to many audiences.

NIJ’s Strategic Direction and Program Areas NIJ is committed to five challenges as part of its strategic plan: 1) rethinking justice and the processes that create just communities; 2) understanding the nexus between social conditions and crime; 3) breaking the cycle of crime by testing research-based interventions; 4) creating the tools and technologies that meet the needs of practitioners; and 5) expanding horizons through interdisciplinary and international perspectives. In addressing these strategic challenges, the Institute is involved in the following program areas: crime control and prevention, drugs and crime, justice systems and offender behavior, violence and victimization, communications and information technologies, critical incident response, investigative and forensic sciences (including DNA), less-than-lethal technologies, officer protection, education and training technologies, testing and standards, technology assistance to law enforcement and corrections agencies, field testing of promising programs, and international crime control. NIJ communicates its findings through conferences and print and electronic media.

NIJ’s Structure The NIJ Director is appointed by the President and confirmed by the Senate. The NIJ Director establishes the Institute’s objectives, guided by the priorities of the Office of Justice Programs, the U.S. Department of Justice, and the needs of the field. NIJ actively solicits the views of criminal justice and other professionals and researchers to inform its search for the knowledge and tools to guide policy and practice.

NIJ has three operating units. The Office of Research and Evaluation manages social science research and evaluation and crime mapping research. The Office of Science and Technology manages technology research and development, standards development, and technology assistance to State and local law enforcement and corrections agencies. The Office of Development and Communications manages field tests of model programs, international research, and knowledge dissemination programs. NIJ is a component of the Office of Justice Programs, which also includes the Bureau of Justice Assistance, the Bureau of Justice Statistics, the Office of Juvenile Justice and Delinquency Prevention, and the Office for Victims of Crime. U.S. Department of Justice Office of Justice Programs

National Institute of Justice 02 JULY Washington, DC 20531 Official Business Penalty for Private Use $300

NCJ 194197