Literature Review Draft 2 Reliability of DNA Profiling
From its origins in 1984, when DNA fingerprinting was first invented by Sir Alec
Jeffreys, DNA fingerprinting has grown to become an essential tool in human identification.
DNA fingerprinting’s uses range from indentifying criminals or victims to matching an organ
donor with their proper recipient. Regardless of the guidelines set in place during the application
of DNA analysis, errors have a chance of occurring. The controversy facing DNA profiling still
continues despite the fact that DNA testing has been accepted by the criminal justice system and
courts as reliable evidence. Given that DNA profile matching is a science based off probability,
it is important to know what actions are taken when DNA is the primary evidence for human
identification. In this paper, the reliability of using DNA profiling for identification will be
examined. The following five literature reviews attempt to support and provide evidence to my
claim.
In a research article by Jobling & Gill (2004), the processes of human identification using
DNA was highlighted. The weight of DNA evidence is explained by match probability (Pm) or
the probability that a second person will have the same DNA profile (Jobling & Gill, 2004, p. 2).
Jobling & Gill discussed a method for human identification called Short Tandem Repeats
(STRs).The match probability of the current STR method surpasses the current population of
people on Earth (Jobling & Gill, 2004, p. 5). The STR method has been used in large scale
identifications such as indentifying remains after the 9/11 World Trade Center attack (Jobling &
Gill, 2004, p. 8). Jobling & Gill explain that an estimated 1,000 people might never be identified
due to problems with DNA degradation. The reliability of DNA testing here is convincing. Our
current human identification methods are able to make profile matches with the least likely
chance of the match not being unique. That’s good to hear since DNA fingerprinting is widely
accepted as reliable evidence. The factors that could raise the match probability are good to take
note of as they sometimes can disallow successful DNA profile matches.
Next, the topic of problems facing DNA fingerprinting is addressed by depreciating the
DNA analysis process. In a research article by Varsha (2006), the complications of using DNA
fingerprinting as a tool in criminal investigations was discussed. The article points out problems
that relate to DNA fingerprinting. First, court cases require that the probability of a DNA
fingerprint being unique needs to be high. Next, proper training is needed for collection of
samples and analysis. Also the impurities found with the DNA can hinder the identification
process (Varsha, 2006, p. 7). The reliability of DNA evidence in this case rests upon the people
who work with DNA and problematic environmental conditions. Varsha, Jobling, and Gill would
agree that a convincing match probability is important weight.
Additionally, the topic of DNA evidence insufficiency is scrutinized in regard to its
applicable use in the court system. In a research article by Sucherman (2011), the validity of
“John Doe” DNA Arrest Warrants and unconstitutional claims against their use was talked about.
“John Doe” DNA arrest warrants are used to preserve sexual assault cases where the perpetrator
is unknown but DNA evidence that could be used to identify him was found at the crime scene
(Sucherman, 2011, p. 3). Sucherman argues that DNA evidence is insufficient in telling us the
events that took place during a crime, but it’s useful for identifying people. In the case of People
v. Robinson the court reviewed claims of “unlawful collection of DNA evidence” and “statute of
limitations” violations (Sucherman, 2011, p. 3). Robinson was tried for a sexual assault case in
1994- six years after the fact. Even though Robinson’s constitutional rights were violated, the
DNA evidence identifying him as the criminal was very convincing. An expert witness at the
trail explained that the probability of the incriminating DNA pattern matching two people at 13
loci was 1 in 630 quadrillion (Sucherman, 2011, p. 3). The reliability of DNA testing shown here
concerns its use in finding unknown criminals. With disregard to claims of injustice, DNA is
accepted as incriminating evidence. This article agrees with Jobling & Gill’s claim of DNA
testing having a low probability of matching a DNA profile with two people.
Next, the topic of using DNA analysis for exonerations is examined in regard to its
repercussions. In a research article by Berger (2006), the impact DNA exonerations are having
on capital punishment, incarceration, and court rulings was addressed. For example, DNA
exonerations are the reason behind the diminishing public approval of the death penalty (Berger,
2006, p. 2). The possibility of sending innocent people to their death can leave a bad aftertaste.
DNA fingerprinting was a promising tool for exonerations. In the 1990’s, to reduce the risk of
error in DNA testing, forensic laboratories who handle DNA were subjected to guidelines set by
the FBI (Berger, 2006, p. 2). Even though guidelines were put in place, many mistakes as a result
of fraud or incompetence of specific analysts were discovered by post-conviction examinations
of DNA analyses (Berger, 2006, p. 3). Berger suggests that flawed DNA analyses may be at fault
for an unknown number of convictions. She argues that crime laboratories need to improve their
procedures for hiring, training, supervision, and review of their personnel in order to make sure
that flawed DNA analyses are not conducted. The reliability of DNA testing shown here relies on
the implementation of analysis techniques in laboratories that deal with DNA. It is a shame that
some analysts have made fraudulent DNA analyses. If they had just done their job properly, then
innocent people would not have to go to prison. Hopefully the post-conviction analyses being
carried out will catch any mistakes and repair the damage done by flawed DNA analyses.
Finally, the topic of implementing DNA innocence testing guidelines is evaluated in
terms of effectiveness. In a research article by Weathered (2004), the difficulties facing DNA
exonerations when challenging the reliability of evidence in a DNA related case were discussed.
The estimated percentage for wrongful convictions in the United States is .5 – 5% (Weathered,
2004, p. 3). As of 2004, 148 post-conviction exonerations in the United States were done using
DNA evidence (Weathered, 2004, p. 2). Considering the population people incarcerated in the
United States (2 million as mentioned in Berger’s article), this number does not appear to
represent the estimated percentage of wrongful convictions. According to Weathered, DNA
evidence in exoneration cases was only available 20% of the time. As a solution to the wrongful
imprisonment problem, programs called “innocence projects” were created. The “innocence
projects” were institutions whose primary purpose was to get innocent people out of prison.
Applicants to the innocence projects faced issues regarding their possible exoneration such as not
having the right of crime scene evidence perseveration, slow or no access to evidence, and no
right to have DNA innocence testing conducted at forensic labs exonerated (Weathered, 2004,
pgs. 9-10). An example of these issues can be seen in the case of Larry Johnson. In 1984,
Johnson was charged with rape and sodomy and spent 18 years in prison before he was
exonerated (Weathered, 2004, p. 10). Johnson had applied to the Innocence Project in New York
in 1996, but was not granted post-conviction testing until 2002. Weathered states that forensic
evidence has been either lost or destroyed for about 75% of old cases in the United States. To
combat the issues facing innocence testing, new laws were created in the United States and
Australia to insure that potential evidence that could prove innocence is well preserved and is
accessible when needed (Weathered, 2004, p. 2). The reliability of DNA in this case falls upon
our justice system’s ability to preserve evidence and conduct post-conviction DNA testing for
people applying to Innocence Projects. It is a sad thought that many innocent people are
suffering in prison without a simple means to prove that they were wrongly convicted. DNA
testing is not at fault for the wrongful convictions. In fact, DNA fingerprinting has been helpful
in providing some people with the evidence they need to get exonerated. If the new laws created
for innocence testing are successful, then more of the .5 – 5% of people wrongfully convicted in
the United States will get their freedom back.
All the results indicate that DNA fingerprinting has already been accepted as a reliable
source of evidence but complications involving the analysis and use of such evidence need to be
taken into account. It is evident that the main argument for DNA fingerprinting’s being
unreliable is its human related problems. Berger and Weathered would branch of from there and
argue that the Criminal Justice System is at fault for the slow progress of exonerating innocent
people. Some of the problems with DNA fingerprinting listed in Varsha’s article are the same as
the main problems in Berger’s article.
References
Berger, M. A. (2006). The Impact of DNA Exonerations on the Criminal Justice System. Journal
of Law, Medicine & Ethics, 34(2), 320-327. doi:10.1111/j.1748-720X.2006.00037.x
Jobling, M. A., & Gill, P. (2004). ENCODED EVIDENCE: DNA IN FORENSIC ANALYSIS.
Nature Reviews Genetics, 5(10), 739-751. doi:10.1038/nrg1455
Sucherman, M. (2011). People v. Robinson: Developments and Problems in the Use of "John
Doe" DNA Arrest Warrants. California Law Review, 99(3), 885-913. Retrieved from
EBSCOhost.
Varsha. (2006). DNA Fingerprinting in the Criminal Justice System: An Overview. DNA & Cell
Biology, 25(3), 181-188. doi:10.1089/dna.2006.25.181
Weathered, L. (2004). A QUESTION OF INNOCENCE: FACILITATING DNA-BASED
EXONERATIONS IN AUSTRALIA. Deakin Law Review, 9(1), 277-293. Retrieved
from EBSCOhost.