F rensic MAGAZINE TECHNOLOGY, TRENDS, PRODUCTS, AND SOLUTIONS FOR FORENSIC PROFESSIONALS Vol.2 | No.4 JUNE | JULY 2005 EVOLUTION OF DNA EVIDENCE FOR CRIME SOLVING – A JUDICIAL AND LEGISLATIVE HISTORY HIGH PROFILE CELEBRITY TRIALS AND CRIME TELEVISION SHOWS SUCH AS CSI HAVE HAD A MONUMENTAL EFFECT ON RAISING PUBLIC (AND CONSEQUENTLY, JURY POOL) AWARENESS OF DNA’S ROLE IN THE CRIMINAL INVESTIGATION PROCESS. DESPITE ITS MORE RECENT DRAMATIC APPEAL, THE USE OF DNA EVIDENCE HAS UNDERGONE A CAREFUL, STEADY EVOLUTION TO BECOME A STANDARD FORM OF ADMISSIBLE EVIDENCE IN TODAY’S COURTROOMS. The extensive scrutiny that investigating the use of DNA has been placed on DNA evi- for forensics, to use DNA to dence over the years is due KAREN CORMIER, LISA CALANDRO, AND DENNIS REEDER verify the confession of a 17 not only to the relative new- year-old boy in two rape-mur- ness of the technique in the judicial system, ders in the English Midlands. The tests proved but also to the sheer power of DNA to dis- the teenager was in fact not the perpetrator criminate between individuals and hence to and the actual attacker was eventually caught, convict or exonerate. also using DNA testing. In recent years, legislative issues have The first DNA-based conviction in the become the focus, stemming from the United States occurred shortly after in increased use of DNA databanking and the 1987 when the Circuit Court in Orange movement to allow post-conviction DNA County, Florida, convicted Tommy Lee testing. Andrews of rape after DNA tests matched his DNA from a blood sample Early Days with that of semen traces found in a rape DNA profiling was originally developed as a victim.1 The first state high court to method of determining paternity, in which rule in favor of admitting DNA evidence samples taken under clinical conditions were came two years later in West Virginia.2 examined for genetic evidence that could link parent to child. It In the first years following these groundbreaking cases, first made its way into the courts in 1986, when police in the admissibility of DNA evidence was not largely disputed. England asked molecular biologist Alec Jeffreys, who had begun That began to change once the technique began to 1 JUNE|JULY 2005 F rensicMAGAZINE become more widely used by prosecutors. Soon defense col and methodological validation process were deemed insuf- attorneys began challenging the admissibility of DNA tests. ficient and the evidence was dismissed. Even though DNA testing would grow more ubiquitous in Admissibility Standards the criminal justice system over its first fifteen years in use, In general, two standards are used to judge the admissi- another wave of cases came with advancements in DNA testing bility of novel scientific evidence - the “Frye standard” technology. Specifically, the movement toward abandoning the and the “Daubert standard.” The Frye standard origi- original methodology, restriction length fragment polymor- nates from a 1923 case, Frye v. United States, where the phisms (RLFP) using VNTR loci, in favor of polymerase chain court ruled that, to be admissible, scientific evidence reaction (PCR) and sequencing technology using short tandem must be “sufficiently established to have gained general repeats (STRs) gave defense lawyers another opportunity to acceptance in the particular field in which it belongs.”3 challenge the admissibility of DNA evidence by calling into The Daubert standard is more recent, derived from the question the new methodology’s reliability for determining 1993 case Daubert v. Merrell Dow Pharmaceuticals, DNA identification. where the Supreme Court went beyond Frye to say that These issues were, for the most part, resolved in a string of evidence must have sufficient scientific validity and relia- cases around the year 2001 where courts repeatedly supported bility to be admitted as relevant “scientific knowledge” the method as reliable and accepted, with some recommending that would “assist the trier of fact.”4 that the technique in general should no longer be the subject of judicial scrutiny,9,10,11 even in one Colorado case where the Challenges to Admissibility DNA evidence was initially found inadmissible based on ques- People of New York v. Castro was a landmark murder case tions about the DNA testing kit’s validation, but on appeal commonly cited as the first serious challenge to the admissi- ruled generally accepted and admissible.12 bility of DNA evidence. During the pre-trial hearing in the New York Supreme Court, DNA evidence from a bloodstain The Emergence of DNA Databases on the defendant’s watch was in question. The court deter- In addition to important court cases scrutinizing the reliability mined that DNA identification theory, practice, and tech- of DNA evidence upon review of laboratory methodology and niques are generally accepted among the scientific communi- validation processes, the introduction of the Federal Bureau of ty, and that pre-trial hearings were required to determine Investigation’s (FBI) Combined DNA Index System (CODIS) whether the testing laboratory’s methodology was in align- forensic DNA database – mandated by the federal DNA ment with scientific standards and produced reliable results Identification Act of 1994, provided another set of pressures on for jury consideration. forensic laboratories to ensure their methodologies were sound However, the testing laboratory’s procedures were called and validated. into question and expert testimony revealed that the lab had All DNA laboratories that are federally operated, receive failed to use generally accepted, reliable techniques that federal funds, or employ software prepared for the CODIS are could prove the blood on the watch was that of the victim. required to demonstrate compliance with the standards issued Interestingly, the Court did allow the DNA tests that ruled by the FBI. (Note: For a description of these and other stan- out the blood as that of Castro – upholding the DNA tests for dards that have governed DNA testing laboratories, see our exclusion but not inclusion since the process for determining earlier article from this series “Evolution of the Quality a match is more complex than ruling out a match. Assurance Documents for DNA Laboratories” Forensic Because of its exhaustive process attempting to analyze the Magazine, February/March 2005.) admissibility of this DNA evidence, in its opinion the New Similarly, the Violent Crime Control and Law Enforcement York Supreme Court outlined recommendations and require- Act, implemented in 1994 advocated for uniform standards to ments for future discovery phase proceedings, including the be used for forensic DNA testing. It further provided federal provision of copies of all laboratory results and reports to the support for state and local law enforcement agencies to improve court and defense, explanation of statistical probability cal- their DNA testing capabilities. culations, explanations for any observed defects or laborato- ry errors, and chain of custody of documents. Development of All Felons Databases While the late 1980s and early 90s saw a number of judi- In addition to CODIS, all 50 states maintain DNA databases. cial challenges to the admissibility of DNA evidence, most The types of profiles that are included vary from state to state, important cases established the admissibility of DNA evi- with a general trend toward expanding the crimes justifying dence, when properly collected and analyzed.5 Where inad- inclusion. In 1990, Virginia became the first state to enact an all missibility was found, it was largely due to questions about felons’ law that required DNA from anyone convicted of a the validity of techniques used to derive or interpret the DNA felony. Most states at that time included only certain offenses, profile (such as population statistics), or about the reliability such as sexual assault. By 1999, six states had All Felons data- of the lab or technician performing the analysis.6,7 bases and today there are 38 states with this legislation; the In one such case, the Supreme Court of Minnesota majority of the remaining states have some legislation in review acknowledged the scientific acceptance of DNA testing, but to expand their DNA databases to include all felons. stated that “admissibility of [DNA] test results in a particular The expansion of DNA databases has led to a growing case hinges on the laboratory's compliance with appropriate number of “cold hit” cases, where no suspect has been iden- standards and controls.” 8 In this case, the laboratory’s proto- tified, but samples from a crime scene submitted to the local, 2 F rensicMAGAZINE JUNE|JULY 2005 state or federal DNA database result in a match from a pre- dards. Under the law, CODIS is expanded to allow state crime viously convicted offender. In 2002, Virginia became the labs to include the DNA profiles of all individuals whose DNA first state to execute a criminal convicted of murder and samples were lawfully collected, including samples from rape based on a “cold-hit.” As testimony to the importance arrestees and juveniles adjudicated delinquent. The law also of DNA databases, the convicted felon, James Earl extends the statute of limitations at the federal level in cases Patterson, was already serving time for a rape and was where DNA testing implicates a perpetrator until the time that scheduled to be released in 2004. perpetrator’s actual identity is discovered. Emergence of “John Doe” Warrants Conclusion In addition to facilitating “cold hits,” DNA database legislation The utility and power of DNA as a tool to convict criminals or has given rise to a new type of arrest warrant – termed “John exonerate suspects has been greatly supported by the careful Doe” or “DNA” warrants because the warrant is issued not for legal reviews and stringent quality assurance guidelines that a named person, but for a genetic code identified as part of a have been developed over the course of nearly twenty years.