The use of DNA in solving crimes has become widely accepted. DNA is now routinely presented in courts as evidence. DNA evidence had helped to identify crime victims and has helped put criminals behind bars. Additionally, DNA is now helping lawyers in defending innocent clients. In many cases, DNA tests have proven the innocence of many prisoners who have been in jail for years. This includes prisoners who would otherwise have been executed.
This paper examines the growing role of DNA testing in the criminal justice system. The first part of this paper discusses the scientific merits of DNA testing, and how these tests contribute significantly to forensic tests and criminal prosecutions. The next part of the paper discusses the precautions that must be taken, to ensure that DNA testing is accurate.
In the conclusion, this paper discusses how DNA testing should be used as a tool for criminal justice. In addition to using the tests to ensure guilt, this paper argues that DNA testing should also be a viable option made available for people who would like to prove their innocence.
Prior to DNA tests, many prosecutors relied on eyewitness testimony to solve crimes. The reliance on witnesses, however, presented was a severe limitation in many prosecutions. Witness testimony could be tainted by bias, prejudice or mistakes.
Months may go by before a trial can commence, which may cloud the memory of many potential witnesses. In addition, many professional killers are able to commit murders and other crimes without any witnesses altogether (Gowen 2002).
In one example, in 2002, DNA evidence led to the conviction of a sex offender for a rape committed in 1982. The same test cleared Bernard Webster, who was convicted based largely on the testimony of the victim and two witnesses. Webster, who had served 20 years, was freed after DNA from the crime ruled him out as a suspect (Gowen 2002).
The use of DNA testing to present biological evidence of a person's guilt or innocence presents a viable alternative to eyewitness testimony. Since DNA or deoxyribonucleic acid is an essential molecule present in every body cell, it becomes more difficult for criminals to erase all evidence of their crime (American Civil Liberties Union 2002).
Further more, since every individual's DNA is unique, DNA is a reliable identifier. Except for identical twins, every person's DNA is unique. Unlike other identifying marks like fingerprints and facial features, DNA cannot be altered. Modern science can thus distinguish between individual DNA samples with great accuracy, making DNA a much-improved version of fingerprinting (ACLU 2002).
Scientific techniques are also improving the reliability and efficiency of DNA testing. Currently, biological evidence must be properly collected and preserved to be accurate. New advances, however, allow forensic scientists are using mitochondrial DNA, which is more plentiful than regular nucleic DNA. This new technique allows investigators to extract DNA evidence from smaller, older and less well-preserved biological evidence fragments (Cohen 1997).
This development will thus help in revisiting older death penalty cases, where the DNA collected was either too small or too degraded for testing.
In summary, because DNA is plentiful and unique to each individual, DNA testing is a much more reliable method of investigating and prosecuting crimes. New scientific techniques will only improve the accuracy of these tests. The use of DNA testing is thus a powerful tool to help prove the innocence of prison inmates who are convicted largely through eyewitness testimony.
Many scientists caution, however, against seeing DNA testing as the ultimate scientific test. After all, as Cohen (2003) states, "the evidence has proven only as reliable as those doing the testing."
Since it was first used in criminal investigation in 1987, there have been several high-profile mistakes that call the reliability of DNA testing -- and scientists -- into question.
First of all, not all DNA evidence collected is examined in labs. However, the National Institute of Justice finds that as many as 350,000 DNA samples from homicide and rape cases remain unexamined. This figure represents a 20-year backlog. Despite a proposal by U.S. Attorney General John Ashcroft to commit $1 billion to clear this backlog, many lab records remain out of date (Cohen 2003).
Many police departments also need to overhaul their DNA testing procedures. There have been many cases where carelessness or shoddy DNA testing has led to false convictions. In January 2003, for example, the crime lab in the Houston Police Department (HPD) was shut down after an investigative report revealed mishandling of evidence and a neglect of protocol. At least seven convictions were vacated after the news report, including the wrongful rape conviction of a man who was already serving a 25-year sentence (Cohen 2003).
The problem at the Houston Police Department stretches back even farther. The Harris County District Attorney's Office is currently conducting an investigation of the crime lab. Nearly 200 cases wherein DNA evidence was used to exculpate defendants are being re-examined, at taxpayer expense (Cohen 2003).
Similarly, in Las Vegas, the DNA was compromised by a mere clerical error. A man was convicted of two rapes after his name was mistakenly placed on the DNA profile taken to the forensic lab in 2001. This "transcriptional" error was caught in time, but has thrown doubt on the city's crime lab (Puit 2002).
Flawed DNA testing also occurs on the federal level. In 2003, the FBI lab came under scrutiny for the way it performed DNA tests in over 100 cases. In this example, one FBI lab technician's shoddy work or mistakes may have compromised evidence in more than 100 cases, over a span of two years ("FBI Lab Under Scrutiny for Flawed DNA Testing" 2000). Because of these reports, many defense lawyers are calling for an open investigation.
Part of the problem lies in the fact that crime labs do not have to be accredited by any state or federal authority. Since the problems in Houston surfaced, however, many experts are calling for the accreditation of labs and for certification tests for forensic scientists. Currently, only New York, Texas and Oklahoma require that crime labs should be accredited (Cohen 2003).
To compound the problem, there are currently no standardized requirements in evaluating DNA evidence. There are no national standards regarding the size of sample required. Given the growing number of private labs doing DNA testing, this problem is even more significant.
What needs to be done
Experts have made suggestions on how to address the problem that are arising due to DNA testing. Additionally, there have been calls to use DNA testing not only to determine guilt but also to prove innocence.
After the Las Vegas crime lab debacle, investigators have added "levels of review" at the crime lab to guard against clerical and transcriptional errors. This is to guard against more paperwork errors. The Las Vegas crime lab now also mandates a second DNA test be done on a sample, before this sample is entered into the computer database. The computerized transcription DNA samples may also help guard against clerical errors (Puit 2002).
The American Board of Criminalistics (ABC) currently offers a certification exam for forensic scientists. Those who successfully pass the exam will be designated as fellows. The exam covers scientific areas that are important to DNA analysis, such as molecular biology and serology. The exam additionally covers law as applied to forensic examinations (Cohen 2003).
This test, however, is not required, and many forensic specialists feel no need to take it.
Additionally, the time- and dollar-intensive nature of the certification process discourages many labs from undergoing accreditation.
As long as there is no legal requirement, many would-be forensic experts do not have the impetus to devote time and resources to the exam and the review process.
DNA testing would also be more reliable and useful if it was more readily available. Towards this, defense experts are advocating free DNA testing should be made available for all people convicted of capital crimes. Opponents, however, argue that DNA testing for prisoners often cite the costs to the taxpayer as well as the potential for abuse. After all, each DNA test can cost up to $5,000 per inmate ("Free DNA Testing for Inmates" 2000).
Corollary to this, DNA testing also involves collecting samples from crime suspects and maintaining a DNA database. The costs to collect DNA sample from suspects and to process and store these samples can run into millions of dollars. The city of Chicago alone estimates the entire process could cost as much as $15 million annually (Possley and Ferkenhoff 2002).
However, cities like San Diego, California are footing the bill for the DNA tests of inmates. As Riverside county assistant district assistant Randy Tagami notes, "Five thousand dollars is not a significant amount of money to determine the guilt or innocence of an individual" (cited in "Free DNA Testing for Inmates" 2000).
Cities which do not have funds for individual DNA testing will benefit from a budget proposal that sets…