1 OHHS Forensics Snow Packet Name ______Date ______Page 1- Day 1

Types of Evidence

OBJECTIVE: S.HS.FS.2 Distinguish between types of evidence: testimonial, physical: individual and class: quantitative, qualitative.

Two basic types of evidence exist: testimonial and physical (class or individual).

• Testimonial Evidence is a statement made under oath; also known as direct evidence or prima facie evidence. This evidence includes witness testimony and, when gathered by law enforcement or investigators, can be used to build a timeline of events or confirm a suspect’s whereabouts.

• Physical Evidence is any object or item that establishes that a crime has been committed or establishes a link between a crime and its perpetrator or crime and its victim. Examples of physical evidence include a document, a hair, fibers, , soil, and blood.

Class Characteristics are properties of physical evidence that can be associated only with a group and never with a single source. If evidence is determined to possess class characteristics it may serve as a mechanism to reduce the number of suspects, but it cannot be directly connected to one person or source. Examples of class evidence include blood type, fibers, and paint.

Individual Characteristics are properties of physical evidence that can be attributed to a common source with a high degree of certainty. Examples of individual evidence include anything that contains nuclear DNA, toolmarks, and fingerprints.

Types of Evidence

Examples:

Examples: Examples:

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Physical Evidence Description Examples

Class

Individual

Which type of evidence is more reliable: testimonial or physical? Explain why and provide an example. ______

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Classify each piece of evidence as testimonial or physical:

Evidence Classification Evidence Classification Expert testimony by a A ripped blanket found Chemist in a drug case in the victim’s garage DNA collected from Fiber evidence the crime scene collected from a trunk A description of a car Written description of by an onlooker perpetration by victim A knife found in a A gum wrapper found suspect’s vehicle in a wooded area

Classify each piece of physical evidence as class or individual and provide an explanation.

Evidence Classification Explanation A piece from a paper cut into four equal pieces. A piece of from a paper ripped jaggedly in to four pieces. A broken piece of glass from a window found a suspect’s car A footprint left by a brand new pair of Converse All Stars. A ransom note ripped from a notebook. Nuclear DNA

A match taken from a box of matches. The of a kidnapper left at the scene of the crime.

Which is more valuable in court: class or individual evidence? Explain why and provide an example.

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3 OHHS Forensics Snow Packet Name ______Date ______Page 3- Day 2

Locard’s Exchange Principle I

OBJECTIVE: S.HS.FS.3 Analyze modes of transfer and factors affecting persistence of evidence (Locard’s Exchange Principle): indirect, direct

Every Contact Leaves A Trace

• Edmond Locard (1877-1966) Locard was the founder of the Institute of Criminalistics at the University of Lyon in Lyon, France. The Institute of Criminalistics is considered to be the flagship university in the field of . He is most prominently remembered for his cross-transfer principle known as Locard’s Exchange Principle, which states that whenever two pieces of evidence come into contact with each other, there is always an exchange of materials.

• is evidence from a transfer of material, a very small piece of evidence left at a crime scene that may be used to identify or link a suspect to a crime. The value of trace evidence was first recognized by Edmond Locard. Examples of trace evidence include paint, explosive debris, glass, dust and dirt, gunshot residue, blood, and other bodily fluids.

Looking at Locard’s Exchange Principle in Action

Imagine you have 2 children and a cat. You run out to take care of some errands that include stopping at a furniture store, the laundromat, and the house of a friend who has one child and a dog.

What kinds of things might you leave behind?

What kinds of things might you pick up from each place?

If someone robbed your friend’s house that evening while your friend was away, they could place you at the scene of the crime. How could you defend yourself to the police?

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Give examples of trace evidence and describe how the evidence could be left at a crime scene.

Example How could it be left at a crime scene?

Snow Day Lab: Locard’s Exchange Principle and Trace Evidence

Instructions: You will need to select a new shirt or one that has been worn little and just washed and dried. Inspect the shirt carefully before putting it on for ‘trace evidence’ and remove what you can. Wear the shirt for at least four hours and keep track of your activities during this time. After you take the shirt off, inspect it under a bright light. List anything you find on your shirt below (hairs, fibers, etc.) and how you think those pieces of ‘evidence’ got on there.

‘Evidence’ found on shirt How did the evidence get on the shirt?

Explain how the snow day lab demonstrates Locard’s Exchange Principle and the value of trace evidence. ______

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Locard’s Exchange Principle II

OBJECTIVE: S.HS.FS.3 Analyze modes of transfer and factors affecting persistence of evidence (Locard’s Exchange Principle): indirect, direct

Your DNA goes places you have never been: What does this mean for forensic scientists interpreting DNA found at a crime scene?

During a criminal investigation, items are commonly examined for DNA to try to identify a potential suspect. But is this DNA really from someone involved in the crime or has it got there through innocent means? In recent years, the sensitivity of DNA profiling technology used by forensic casework laboratories has increased dramatically. This means that we can now detect very small traces of DNA. Such DNA is commonly referred to as ‘touch DNA’, but since touching is not the only way to leave DNA, the term ‘trace DNA’ is more appropriate.

Although TV shows would have us believe that the DNA always comes from the culprit, in reality, there are various ways DNA can be left on an item (Fig. 2a), many of which may have nothing to do with the crime in question. DNA can be left on surfaces directly through physical contact, such as handling a knife or wearing a jumper, or through activities, such as speaking and coughing. DNA can also be transferred indirectly (Fig. 2b). Scientific research has shown that DNA from a person can end up on items that they have never touched, and in some situations, in a room they have never been to. Whilst it is known that such transfers can occur, scientific research is only just starting to understand the effect indirect transfer has on the interpretation of DNA from a crime scene.

It is our view that, under many casework situations, there is currently insufficient published research to support the formation of an opinion on how DNA came to be on a surface of interest. Let us take so-called ‘wearer DNA’ as an example. In casework, items of clothing are routinely examined with the view of recovering DNA from the wearer of those clothes (Fig. 1). However, with only a handful of research papers published on this subject, it is unclear whether the DNA recovered comes from the regular wearer of the clothing, the most recent wearer (i.e. the wearer at the time the crime) or indirect transfer events. This issue is further complicated by the finding of DNA mixtures, that is, DNA from more than one person. Forensic scientists are therefore left with the question: ‘Which DNA profile was deposited at the time of the crime and how did it get there?’

Fig. 2. Trace DNA can be transferred to a surface at a crime scene through a variety of ways. (a) Transfer includes the deposit of dilute body fluids (e.g. blood that is so dilute we cannot detect it as blood), direct contact, activities in the vicinity of the surface, and indirect transfer. (b) Indirect transfer occurs when DNA from a person is transferred to a surface via an intermediate person or object, or indeed people or objects. 6 OHHS Forensics Snow Packet Name ______Date ______Page 6- Day 3 When a forensic scientist addresses this question for the court, it is imperative that their testimony is derived from empirical data and not solely a personal opinion. Such empirical data should ideally be published so that the data are subjected to the scientific peer review process. This process is designed to ensure that only rigorously conducted research is made available to the scientific community. Publication therefore enables only good quality data to be relied upon by forensic scientists when they interpret evidence.

Despite the lack of published research, scientists working for providers of forensic science to the police in the UK and Ireland argue that a reliable dataset is available for the interpretation of ‘wearer DNA’. Their claim comes from their reliance on those few published papers, unpublished data and their casework experience. There are serious issues with relying on unpublished data, as the data have not undergone peer- review, nor has the research been shared with the scientific community. This tends to deny scientists working for the defense a proper consideration of the scientific case against the defendant. Reliance on casework experience to support expert opinion is even more dangerous. A forensic scientist should not provide the reason for their opinion as ‘x years of casework experience’ without actually explaining how this experience can inform their interpretation of the evidence.

To attempt to reconstruct a crime, it is our opinion that experimental data are needed to distinguish between the different ways that DNA can be deposited. Our research at UCL’s Centre for the Forensic Sciences aims to provide that data, by looking at various scenarios that affect how DNA can be deposited on items commonly found in casework, to see whether the DNA recovered can give clues as to how it got there.

1. Why is ‘trace DNA’ a more accurate term than ‘touch DNA’?

2. Explain what happens during indirect DNA transfer and give an example.

3. What are ‘DNA Mixtures’? How are they a problem for investigators?

4. Why is relying on unpublished data a serious issue? Provide 2 reasons and explain.

5. Summarize the main idea of the article in one paragraph. Then write one sentence giving your personal reaction to what you have read.

6. On a separate paper, write a 3 paragraph fictional story in which an indirect DNA transfer results in a wrongful conviction. Be prepared to share your story aloud in class when you return to school.

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Fingerprinting I

OBJECTIVE: S.HS.FS.5 Validate, classify, and analyze fingerprints as individual evidence: type, pattern, minutiae.

Why Use Fingerprints in a Criminal Investigation Fingerprints obey three fundamental principles. These principles are:

• 1- A fingerprint is an individual characteristic. It is yet to be found that prints taken from different individuals possess identical ridge characteristics.

• 2- A fingerprint will remain unchanged during an individual's lifetime.

• 3- Fingerprints have general characteristic ridge patterns that permit them to be systematically classified.

What are the Basic Patterns into which Fingerprints are Classified?

• Arches crate a wave-like pattern and include plain arches and tented arches. Tented arches rise to a sharper point than plain arches. Arches make up about five percent of all pattern types.

• Loops prints that recurve back on themselves to form a loop shape. Divided into radial loops (pointing toward the radius bone, or thumb) and ulnar loops (pointing toward the ulna bone, or pinky), loops account for approximately 60 percent of pattern types.

• Whorls form circular or spiral patterns, like tiny whirlpools. There are four groups of whorls: plain (concentric circles), central pocket loop (a loop with a whorl at the end), double loop (two loops that create an S-like pattern) and accidental loop (irregular shaped). Whorls make up about 35 percent of pattern types.

How Many Kinds of Fingerprints Are There?

• VISIBLE PRINTS are prints made by fingers touching a surface after the ridges have been in contact with a colored material such as blood, paint, grease, or ink.

• PLASTIC PRINTS are ridged impressions left on a soft material such as putty, wax, soap, or dust.

• TRUE LATENT PRINTS are invisible print impressions caused by the perspiration on the ridges of one's skin coming in contact with a surface and making an invisible impression on it. Perspiration contains water, salt, amino acids, or oils and easily allows impressions to be made.

How

The Automated Fingerprint Identification System (AFIS) is a biometric identification (ID) methodology that uses digital imaging technology to obtain, store, and analyze fingerprint data. The AFIS was originally used by the U.S. Federal Bureau of Investigation (FBI) in criminal cases. Lately, it has gained favor for general identification and fraud prevention. 8 OHHS Forensics Snow Packet Name ______Date ______Page8- Day4

1. What are fingerprints? Why are they useful in criminal investigations?

2. Give one reason that each of the fundamental principles of fingerprinting is important to forensic investigators.

1-

2-

3-

3. What is a Visible Print? Give an example of how one may be left at a crime scene.

4. What is a Plastic Print? Give an example of how one may be left at a crime scene.

5. What is a Latent Print? Give an example of how one may be left at a crime scene.

6. Describe the three main fingerprint patterns and explain how you would identify each.

7. Create a pie graph demonstrating the frequency of each of the 3 main fingerprint patterns.

8. What is AFIS? How is useful outside of the field of forensics? Explain.

9 OHHS Forensics Snow Packet Name ______Date ______Page 9- Day 5 Fingerprinting

OBJECTIVE: S.HS.FS.5 Validate, classify, and analyze fingerprints as individual evidence: type, WeighingForensicpattern, minutiae. Evidence Fingerprints As As anyone who's ever read a crime novel or watched a cop show knows, there's nothing like a fingerprint to convict the guilty and exonerate the innocent … except, that is, when it doesn't. Long the unquestioned standard of identification, fingerprinting is coming under fire, and some courts are taking notice.

Fingerprints - they are a universal symbol of identity. The ridges which allow us to grasp objects form a complex mix of whorls, arches and loops, believed to be unique to each person. Not even identical twins have identical fingerprints. Which is why fingerprint analysis plays a huge role in solving crimes.

Once a cop, now a criminology professor at the University of Maryland, Tom Mauriello says the best way to track down criminals is still the old fashioned way: dusting for prints.

"It's the most common physical evidence that we find- at a crime scene," Mauriello said. "'Cause when two objects touch each other they take on characteristics of each other. And there's always fingerprints everywhere."

Fingerprint analysis was first used in an American court to convict a killer in 1911. Since then, as any fan of "CSI" knows, criminal investigation has become a lot more high-tech. After almost a century, fingerprint analysis remains a widely-accepted forensic tool. But that may be about to change.

"Without question, fingerprint evidence is considered to be, by juries, actual evidence of guilt, incontrovertible evidence of guilt. And, unfortunately, the reality is far different than that," says attorney and forensic expert Patrick Kent. Kent, who's with the Maryland Public Defender's Office, says that while DNA evidence is a science, fingerprint analysis is basically an art. "It's never been tested," he said. "It's never been shown to be accurate. They don't even have a standard way that they do fingerprint comparisons."

"Are you saying fingerprint evidence shouldn't be allowed?" Moriarty asked.

"My answer, unequivocally, is that it should not," Kent said. And in a decision last fall that shocked lawyers across the country, a judge in Maryland agreed. She threw out the fingerprint evidence tying the defendant Brian Keith Rose to murder.

Glen Langenburg, a fingerprint examiner with the Minnesota State Crime lab, says the jury in that case was actually being denied very valuable evidence. "I'm not saying that it is foolproof," Langenburg said, "and is that the standard, that in order to use evidence in court it must be perfect? I mean the irony is, eyewitness testimony gets in every time. I mean, no one ever challenges eyewitness testimony."

The judge's decision in the Rose case could jeopardize thousands of criminal investigations nationwide.

"She called fingerprint evidence 'a subjective, untested, unverifiable identification procedure.' How do you respond to that?" asked Tom Bush of the Federal Bureau of Investigation. "I don't believe there's evidence to support that type of decision."

Tom Bush runs the FBI's West Virginia complex which processes as many as 140 thousand fingerprints a day. He says the department has been using prints to catch criminals for more than 80 years, which means a lot of bad guys (and their fingers) have left a lasting impression, like Al Capone, Pretty Boy Floyd and George "Machine Gun" Kelly.

Today, with the automated fingerprint I.D. system which stores tens of millions of prints from criminal arrests and employment background checks, analysis can take just minutes. Police from around the country can contact the system and get a response in just hours.

And how reliable is this system? 10 OHHS Forensics Snow Packet Page 10 Day 5 "We believe our system to be in the high 98-percentile accurate," Bush said. But if fingerprint analysis is so accurate, why did the Baltimore County judge in the Brian Rose case refuse to allow it as evidence? Because of what happened to another man in Portland, Oregon.

On May 6, 2004, FBI agents came to Mona Mayfield's home with a search warrant. "They sat at the kitchen table and the gentleman opened up his briefcase and he said, 'This bag was found in the van, 20 minutes away from the Madrid Spain bombing,"' Mayfield said. "'And your husband's fingerprint was on it.”

"It was surreal. It was just surreal. My first impression, 'No way. There's gotta be a mistake.” Just two months earlier, terrorists had bombed four commuter trains in Madrid, killing almost 200 people. An international investigation led to Brandon Mayfield, Mona's husband, an American lawyer who converted to Islam. Mayfield was arrested after a smudged partial print, found on a bag of detonators, was matched to his - not by one FBI examiner, but three.

"I honestly felt that I was being framed," Brandon Mayfield said, "because I hadn't been out of the country for ten years." Mayfield, an Army veteran, had no criminal record and no ties to terrorist groups. His lawyer brought in an independent examiner with the hope of clearing his name. That person, as well, told Mayfield, "It's your fingerprint. That was a very dark day for me, to say the least. I'd probably been in jail in lockdown for over two weeks. I was tired. I was just being worn thin." Mayfield's family was in a quasi-lockdown as well. Mona said people were thinking she was married to a terrorist. "I didn't want to let my kids out of the house," she said. "I didn't want to send them to school. I was afraid for their safety."

Two weeks after Mayfield's arrest, Spanish investigators found the man to whom the fingerprint really belonged. And if Spanish police hadn't found the real source of that print, where would Brandon Mayfield likely be today? According to Patrick Kent, “There’s no question that Mr. Mayfield would be sentenced either to life or sentenced to death. No question."

It turns out a partial, distorted print, like the one the FBI had, often yields multiple potential matches. In fact, when the Madrid print was put into the government's automated system, 20 different prints with similarities came up, including Mayfield's. After the first FBI examiner mistakenly matched the print to Mayfield, the other two confirmed it. The Bureau has since promised "procedural reforms," but Kent says he isn't buying it. "The problem is, how many Mayfields are there?" he said. "If the best, by their admission, can make such a glaring error in a high-profile case when they knew the world was watching, what is happening in the counties, in the countryside, in areas where we don't, quote, 'have the best of the best?'"

But examiner Glen Langenburg believes this case is not the norm: "I'm always concerned if an innocent person has to go to jail, of course. But I not concerned it's a rampant issue, that this is happening every single day, that people are [wrongly] going to jail on fingerprint evidence. I just don't believe it."

Brandon Mayfield was released and received a public apology from the FBI - along with a $2 million legal settlement. "I was looking at much more severe consequences, and had no idea and felt totally helpless and had no idea how my family was gonna take care of themselves, or what's going to become of me," he said.

"I just want to leave it in the past," Mona Mayfield said, "but of course, it's gonna affect me, it's always gonna affect me. I mean, even for my children, it's always going to affect them for the rest of their lives."

As for Brian Keith Rose in Maryland, he's still facing murder charges. The case has now been moved to federal court where the judge is expected to allow in the fingerprint evidence."Mr. Mayfield is not an aberration," Kent said. "Mr. Mayfield is a public face of many people in jail. It leaves me sleepless, quite candidly, because in fact it not that it just scares me to death, its evidence that they use to put people to death.”

1. In this story, fingerprints, which have historically been a widely accepted forensic tool, have been subjected to questioning. Explain the argument Patrick Kent, Maryland Public Defender and forensic expert, had about fingerprinting being an art and not a science. 2. Did the judge agree or disagree with Kent? Explain why. 3. How can this decision jeopardize other criminal investigations, current and past? 4. Tom Bush, FBI, had a convincing argument for using fingerprint evidence. Explain his argument.