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(Full) DNA--Crime Scenes to Courtrooms

The effects and programs of contemporary DNA forensic science and law

Joshua Thurmond

on 16 January 2016

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Transcript of (Full) DNA--Crime Scenes to Courtrooms

Crime Scene to Courtroom

Why is DNA Important to you?
It saves time
It saves money
It promotes justice
and prevents crime
Why is DNA Important?
Our team went to the UK in 2006:
Obtained their familial search protocol and studied their program.
Tried to convince the FBI to research a familial search program for the US.
Worked with the California AG to change the state’s policy to allow familial searching and sharing this information with law enforcement.
Searched all unknowns against Denver’s DNA database.
Used a familial search software.
In five separate cases there was a 90% chance that two individuals were related.
Y-STR DNA testing showed that the individuals had the same Y-STR type.
The search showed that there was a 90% chance that a DNA profile in an unsolved burglary came from a male offspring of a known sample.
The father was in the DNA database for a 2002 aggravated assault.
Y-STR DNA types matched.
Developed a Familial Search Software Program.

Total cost = $50,000 (including the purchase of a dedicated laptop).


Familial Search Policy
Persuaded the Colorado Department of Public Safety and
the Attorney General to develop a Familial Search Policy and
worked with them to create it.
Presented this policy to the Governor and leaders in the legislature.
The Details:
85% of CODIS matches are obtained within same state.

No statute was necessary.

Was “developed keeping privacy concerns in mind, while at the same time providing information that may be useful in solving a violent offense and prevent potential victimization.”

Applies to arrestee and convicted offender databases.

Absent exigent circumstances, contacting family members/relatives should be the last resort in this type of investigation.

First obtain information via public and/or law enforcement authorized databases before contacting these individuals.
Conducted a search of all forensic unknowns against the Colorado DNA database (about 2,000 against 80,000).

Used our familial search software program.
$2,500 per search - assuming 20 Y-STR follow up tests (includes personnel costs and Y-STR testing reagents).

$7,000 per search - assuming 200 Y-STR follow up tests (includes personnel costs and Y-STR testing reagents).

This does not include the cost of any follow up investigation.
Denver DNA Database Familial Searches:
First Conviction in the US
A 90% chance that the DNA profile from a car break-in and a DNA profile in the local DNA database from a convicted car thief were from brothers.

Y-STR DNA types matched.

A conventional investigation led to the car thief’s brother and a warrant was obtained for the brother’s DNA.
The brother’s DNA matched the DNA from the crime scene.

Jaimes-Tinajero was charged with two car break-ins and pled guilty.

This is the first conviction in the United States where the results from a familial search software program aided in solving a crime.
Luis Jaimes-Tinajero
Car Thief
Mitch Morrissey
Cost to the Lab of a Familial Search and Y-STR Testing
DNA evidence is found in the most violent crimes… Murders, Sexual Assaults, Sexual Assaults on Children.

90% of the victims of crimes where DNA evidence is critical are women.

The next largest percentage of victims are children.

The innocent are exonerated.
Reached Out to 27 Jurisdictions Across the US!
DNA Exonerations Become Cold Cases
In 81 of the first 212 exonerations, DNA led to the real perpetrator.

Rape victims and families of murdered victims deserve answers.

The wrongfully convicted deserve answers.

Familial investigations may provide those answers.
Y-chromosome Short Tandem Repeat (Y-STR)

1. The Y-STR profile represents a paternal relationship due to the Y-chromosome being inherited intact by the son from the father.

2. Use Y-STRs to obtain a male DNA profile from samples with a high amount of female mixed with a low amount of male DNA or to clarify how many male contributors are in a mixed DNA sample.

3. For familial searching, Y-STRs provide a tool to determine if the source of male DNA at a crime scene has a paternal relationship with a male offender.
Mitochondrial DNA (mtDNA)

1. mtDNA is located in the mitochondria, the “powerhouse” of the cell, and children inherit all of their mtDNA from their mother.

2. Use mtDNA to test samples where nuclear DNA is broken down or not present (i.e., old bones and hair shafts), since mtDNA is present in the cell in 1000s more copies than nuclear DNA.

3. For familial searching, mtDNA provides a tool to determine if the source of DNA at a crime scene has a maternal relationship with an offender.
On ten separate occasions we successfully identified the individual who left DNA at a crime scene.

Denver District Attorney

But wait, we are getting ahead of ourselves...
It begins with evidence collection.
Sources of DNA
Inherited Genetic Material:
Unique to an individual - except identical twins.
Present in every cell - except RBCs.
Consistent throughout an individual.

Inherited Genetic Material:

Unique to an individual - except identical twins.
Present in every cell - except RBCs.

Consistent throughout an individual.

Often referred to as the “Blueprint of Life”.

The blueprint contains a complete set of instructions for the make-up of a human.

This information is passed on from generation to generation.
If you were to take a closer look into the human body…
epithelial cells
Nuclear DNA (nucDNA)
Where does nucDNA come from?
Inherit 1/2 from mom (Egg)
Inherit 1/2 from dad (Sperm)

How does nucDNA differ among us?
Approximately 99.5% of our DNA is the same for all people.

It is the 0.5% of DNA that differs that makes us unique.

Forensic DNA Analysis targets these regions that differ in order to make identifications.
*All cells in the body have descended from a single fertilized egg.
Nuclear DNA is packaged into chromosomes
From MOM
From Dad
DNA: The Genetic Alphabet
Unlike the English alphabet, which has 26 letters, the DNA alphabet has only four letters: A, G, C, and T.

DNA is arranged into long strands of these letters.

If you stretched out the nuclear DNA from a human cell it would measure about 1.5 meters or 78.8 inches in length.
DNA is held together by Base Pairing:
A always pairs with T
G always pairs with C
Nuclear DNA: Three Billion Base Pairs
Specific sequence of the DNA alphabet 2 to 7 letters long.

Repeated in tandem a variable number of times.

The number of repeated segments varies among humans.

STR analysis counts the repeated segments.
Most evidence samples have a small amount of DNA present.
= Polymerase Chain Reaction

Based on methods developed in 1985.

Makes 1000’s of copies of target DNA.

Labels specific areas of the DNA with fluorescent tags.
Thermalcycler = Molecular Xerox Machine
Capillary Electrophoresis
The use of an electrical current
to separate out different sized
pieces of DNA.
The speed the piece of DNA
moves through the polymer
matrix is based on its size.

Smaller moves faster
Larger moves slower
Analysis: STR DNA Genotype
Statistics and Population Genetics
Gives weight to the match.

According to the laws of genetics, the inheritance of each STR marker is an independent event.

The frequencies for each STR marker are multiplied together using the product rule.

Random match probability – estimates rarity of the DNA profile in the U.S. population.
Probability of a Random Match Using 13 CODIS STR Markers
Based on the rarity of the DNA profile, and with a reasonable degree of scientific certainty, the DNA profile from the evidence can be attributed to John Doe.

A finite number of individuals have access to the crime scene.

The random match probability plays a role in this calculation.

We are not saying that this DNA profile is unique in the world just that for the purposes of the case it can be attributed to this suspect.
Source Attribution
Provides Evidence When The Victim Cannot

DNA Helps Reconstruct the Crime Scene

Helps Catch Serial Murders and Rapists

DNA Helps Support the Credibility of a Victim/Witness
Denver Crime Lab
DNA and the LAW

Over 5,000 qualifying cases reviewed

Created efficient system for post-conviction review

Locating and determining the condition of evidence in cases early on

Not holding defendants accountable for the actions of their trial attorneys

Instituting a defendant initiated application process.
A criminal case is filed by referring to an unknown defendant as “John Doe, with a specific DNA profile”.
Prevents the Statute of Limitations from running
Sex Offender Tied to Old Rape Case
Glasser was convicted in two sexual assaults in 1997 and his DNA was put into the database.

DNA matched by the Cold Case Project to a previously unsolved case involving a woman who was kidnapped and sexually assaulted in 1996.

He was convicted and sentenced to 90 years in prison.
DNA Leads to a Murder Conviction from 1980
In 1980 a 22-year-old woman was found raped and murdered in a car in northeast Denver.

The case went unsolved for 30 years, until a cold case review revealed DNA from the crime scene.

An unknown male DNA profile from the rape kit was put into the national database and a "hit" was made identifying Elias as a potential suspect.

Elias denied knowing the victim.

He was convicted of first degree murder.
Kristen Swanson
Roderick Elias
Wayne Glasser
28 states have some form of the law.
Any person arrested for a federal crime is subject to DNA sampling under the Violence Against Women law of 2006.
Denver Familial Search Project
To date, Denver’s Cold Case project has:

Reviewed 5,400 cold cases, resulting in 950 submitted lab requests

Tested 633 cases (317 laboratory requests are now pending)

Analyzed 1300 DNA samples

Submitted 412 DNA profiles to CODIS

Filed over 94 cases (sexual assaults, sexual assaults on children, homicides, burglary, and kidnapping)
Partnered with the Colorado AG's Office and reviewed over 5,000 rapes, murders, and manslaughters to identify cases where post-conviction DNA could potentially exonerate an innocent inmate.
274 people exonerated by DNA evidence
The Basics
Deoxyribonucleic Acid (DNA)
Two year program - 204 case filings
Burglaries down 22%(down 40% over four years)
Familial Searching in the U.K.
In Great Britain, Familial DNA intelligence packages have been produced for 122 specific serious crime investigations.
In 28% of the cases there was a relative on the list (32 out of 122).
In Great Britain, Familial DNA intelligence packages
have been produced for 210 specific
serious crime investigations.
In 19% of the cases there was a
relative on the list (40 out of 210).
Familial DNA Searches in the U.K.
Get Ready for Rapid DNA

Rapid DNA technology automates an otherwise multi-step process that requires specialized expertise and a laboratory to deliver results in less than 90 minutes using a self-contained system.
Rapid DNA analysis enables law enforcement to quickly and definitively identify suspects while they are still in custody.
Watch Your Step! DNA From Dog Feces Used in Triple Homicide Case
He really stepped in it...
DNA from dog feces found on the sidewalk of the house where the killings occurred matched DNA in the dog feces on Stroud’s shoes.

The chance of randomly finding another dog having the same DNA was a one in 10 billion.

Deployed two dogs as weapons to attack the victim before he repeatedly stabbed and beat to the victim to death.

One dog, who was owned by Johnson, left a blood trail when he and his owner ran away from the scene. When police arrested Johnson, his victim's blood was on his hands and there was also blood from his dog on his body.

Saliva from the other dog was discovered on torn clothing found at the crime scene. DNA from both dogs was used as evidence and a dog DNA database was used to show that the probability of seeing the same DNA in another dog is less than one in a billion.

Johnson was found guilty of murder.
Chrisdian Johnson
Cat’s DNA Helps Solve Murder
A woman was murdered and buried in a shallow grave.

Her blood stained jacket was found with several white cat hairs on it.

Her killer lived with his parents and a cat called Snowball.

DNA from the hairs on the jacket matched Snowball.
RCMP found a homicide victim’s DNA in 3 dead mosquitoes.

This was evidence that the victim was killed in the apartment where the mosquitoes were found.
Mounties Use DNA
Jacie Taylor, 19, is found raped and strangled to death in the bathtub of her apartment. Robert Dewey is accused of the crime.
During the trial, experts testify that blood found on Dewey's shirt could be a mixture of Taylor's and Dewey's blood. Questions loom about whether Dewey's blood was already on the shirt and if Taylor's blood is present at all.
October 17, 1996
Robert Dewey goes to prison for life as a complicitor in the rape and murder of Taylor.
Dewey's shirt is retested and Taylor's DNA is not found.

JRP (Denver) find DNA under the victim's fingernails, on a blanket and on the leash used to strangle Taylor point to Douglas Thames.

Dewey is exonerated because prosecutors could not show a connection between Thames and Dewey.

Thames is charged with the murder of Taylor.
William Woody, Special to The Denver Post
Thousands of detective hours were used running down leads.
Over 240 innocent men were exonerated by DNA.
He pled guilty to all counts and was sentenced to 120 years in DOC.
6 rapes, 5 kidnappings, 3 robberies, 1 burglary, and 3 attempted rapes could have been prevented.
Michael Lollis
Results from Katie’s Law from November 2010 to March 2013
If the state had required him to give a DNA sample for his felony forgery arrest from 2004.

Over 600 hits Statewide - a 40% Hit Rate

Denver- 187 DNA hits
29 to sexual assaults
4 to murders - 2 resulting in First Degree Murder convictions.
Misdemeanor DNA Law
They take DNA upon misdemeanor conviction.

30% of the DNA hits in 2012 came from misdemeanor convictions.

In 5½ years since petit larceny has been a DNA eligible offense, DNA samples taken from those convicted offenders has helped solve 965 crimes, including 51 murders, 222 sexual assaults, 117 robberies and 407 burglaries.

4 rapists who were linked to 5 rapes after convictions for failing to pay subway fares.

There are 4,788 unsolved cases in the Colorado state DNA database with no hit.

In 2012, there were 42,727 defendants convicted of misdemeanor offenses in Colorado.

If the law required DNA collection upon misdemeanor conviction more crimes would be solved.

Results of a Denver Study - had Colorado required DNA upon misdemeanor conviction at the time that 4 sexual predators were at large - 13 violent crimes, including 3 murders and 6 sexual assaults, would have been prevented.
Look to New York
The Effects of DNA Databases on Crime
by Jennifer L. Doleac (December 2012)

In 2010, 761,609 offender profiles were uploaded to CODIS.

At $40 apiece, this cost the state and federal governments approximately $30.5 million, but saved $21 billion by preventing new crimes.

DNA databases reduce crime rates, especially in categories where forensic evidence is likely to be collected at the scene (murder, rape, and assault)

The marginal cost of preventing crime suggests that DNA databases are more cost-effective than other common law enforcement tool.
88 serious crimes including murders, rapes, child abandoments and kidnappings have been solved because of familial DNA searches.
Plant DNA Links Murderer to Crime Scene
Mark Alan Bogan charged with 1st degree murder of Denise Johnson

Witness saw Bogan's truck near scene

Police found Bogan's fathers' pager in area

Police found two palo verde pods in the bed of truck

Pods matched pods at scene
Maryland vs. Alonzo Jay King Jr.
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