Title: Lessons Learned from Multi-Perpetrator DNA Cases Edwin Grimsley, Case Analyst - The Innocence Project
1Lessons Learned from Multi-Perpetrator DNA
CasesEdwin Grimsley, Case Analyst - The
Innocence Project
2Why Multi-Perpetrator DNA Cases?
- In cases where the number of perpetrators is
definitively known, DNA testing can conclusively
prove a defendants innocence. - We can definitively know the number of
perpetrators when victim(s) or witness(es)
provide a clear account with a fixed number of
perpetrators. - Because we know number of perpetrators, proving
innocence through DNA differs from un-witnessed
cases.
3- Of the nearly 300 DNA exonerations, there are 22
cases where a victim or witness at the crime
scene said there were multiple perpetrators
involved. - These multi-perpetrator DNA cases represent 29
exonerations.
4Lessons Weve Learned from Multi-Perpetrator DNA
Cases
- Lesson 1 You can prove one of the alleged
perpetrators innocent even when his
co-defendant/alleged co-perpetrator is included
by DNA testing or claims guilt. - Lesson 2 You cannot assume that someone is not
innocent just because they havent requested help
from an Innocence Project. - Lesson 3 Multi-Perpetrator DNA cases can be
broken down into a few core principles.
5Lawrence McKinney
- Lawrence McKinney spent 31.5 years in the
Tennessee prison system for a rape he did not
commit. In 2009, DNA testing excluded McKinney as
one of the individuals involved in a two
perpetrator rape of a single victim. - Michael Yancey, who was McKinneys co-defendant,
wrote to the Innocence Project claiming
innocence. The Innocence Project accepted Michael
Yanceys case in 2007.
6- Lesson 1 You can prove one of the alleged
perpetrators innocent even when his
co-defendant/alleged co-perpetrator is included
by DNA testing or claims guilt.
7Background Info Victim
- 30 years old
- One victim, female
- Lived with boyfriend and two children in Memphis,
TN - Boyfriend at work on the night of the crime
- Victim was asleep in her bed
8Two perpetrators (P1 and P2) enter Vs home
around 5 am.
9P1 and P2 demand money. V refuses. P1 sexually
assaults V in her bed. V reports that P1
ejaculates.
10P2 subsequently rapes V. V reports that P2
ejaculates.
11Both P1 and P2 ejaculate Wed look for two DNA
profiles.
12Victim tells Police I saw two assailants and
both raped me.
V was brought to a hospital where a rape kit was
collected.
13Identification/Arrest
- Victim believed both assailants lived in her
building she identified them as Michael (P1)
and his friend (P2) whom she did not know well. - Michael Yancey (P1) and Lawrence McKinney (P2),
who lived in the building, were arrested within
an hour of the crime.
14Innocence Claims
- Michael Yancey told us that he was not at the
crime scene. Yancey named another man (not
Lawrence McKinney) as the actual perpetrator. - We did not know Lawrence McKinneys claims at the
time of acceptance. McKinney claimed innocence
when DNA sample was collected. - We sought to test DNA profiles of Yancey,
McKinney, and the alternate perpetrator.
15Three scenarios to prove innocence
- Two foreign DNA profiles that excluded V would be
obtained. The profiles would not match Michael
Yancey, Lawrence McKinney, or the victims
boyfriend. - Two foreign DNA profiles that excluded V would be
obtained. One profile would match Lawrence
McKinney and a second profile would exclude
Michael Yancey and the victims boyfriend. - One foreign DNA profile that excluded V would be
obtained. The profiles would not match Michael
Yancey or Lawrence McKinney. The foreign profile
would be uploaded into a DNA database and hit to
somebody with no connection to Yancey or
McKinney.
16DNA test Results
- The rape kit was not located. Semen was
identified on bedsheets and Vs panties. DNA
mixture of at least two individuals was found on
both the panties and bedsheets and these DNA
profiles were consistent with each other. - Michael Yancey could not be excluded from one of
the profiles and could not be proven innocent. -
- Lawrence McKinney was excluded from both
profiles, proving his innocence.
17Arthur Mumphrey Exoneration
- Co-defendant Steve Thomas admitted his
involvement to the police. Thomas named Mumphrey
as his co-perpetrator. - Two perpetrator rape. Both perpetrators raped a
single victim.
18- Mumphrey, who claimed innocence, hired a local
Houston attorney to pursue DNA testing. Vs rape
kit and underwear were DNA tested. Two profiles
were developed that matched Steve Thomas and an
unknown male. - Mumphrey was excluded and subsequently
exonerated.
19- Lesson 2 You cannot assume that someone is not
innocent just because they havent requested help
from an Innocence Project.
- Lawrence McKinney did not contact the Innocence
Project or other organizations.
20Reasons why innocent defendants/co-defendants do
not contact attorneys/organizations
- Limited knowledge of attorneys or organizations
to contact because of poor jail resources - Mental Health Issues
- Gave Up Fight after Incarcerated
21- Literacy
- Does Not Understand Science or Legal Process
22- Lesson 3 Multi-Perpetrator DNA cases can be
broken down into a few core principles.
23- We must account for every perpetrator alleged to
have participated in the crime. - Two things to look for in Multi-Perpetrator cases
with a live victim/witness - Victim or witness defines number of perpetrators.
- Match each perpetrator seen to a specific profile
on crime scene evidence.
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25 Scenario Trump Card?
- Alternative to the traditional Multi-Perpetrator
theory -
- CODIS/Database hit to someone unrelated.
- Match to alternate perpetrator who committed
crime with another person.