Postconviction DNA analysis
Postconviction DNA analysis (Forensic Science)
The introduction of DNA (deoxyribonucleic acid) analysis revolutionized forensic science and provided law-enforcement agencies with a powerful tool for solving crimes. The proper use of DNA analysis can identify individuals with a higher degree of confidence than is possible with other forensic techniques, and such analysis has led to the conviction of many criminal offenders. Equally important, postconviction DNA analysis has resulted in the exoneration of many persons who had been wrongfully convicted of crimes. Postconviction analysis of DNA evidence may be conducted because access to such analysis was unavailable during the convicted offender’s earlier trial or because advances in analysis techniques since the individual was convicted may provide better evidence than was available at the time of the trial.
(The entire section is 121 words.)
Background (Forensic Science)
As a tool of forensic science, DNA analysis has a relatively short history. It began in 1985 in Great Britain, when Alec Jeffreys, a geneticist, stumbled onto the use of DNA markers (restriction fragment length polymorphisms, or RFLPs) for personal identification while searching for disease markers in human DNA. He saw the potential for the method’s use in criminal and civil investigations and coined the term “DNA fingerprinting,” later explaining that he chose the term in a “deliberate move to emphasize the new forensic paradigm” that he foresaw. In April, 1985, Jeffreys was asked by Britain’s Home Office to use DNA fingerprinting to solve an immigration dispute regarding the family identity of a boy. Although the blood group evidence supported the boy’s claim of true kinship with the family, it was not convincing. The findings of the DNA analysis performed by Jeffreys and his colleagues supported the authenticity of the boy’s claim.
The publicity that accompanied this case not only opened a floodgate of inquiries from immigrant communities over previously disputed cases but also led to the introduction of the use of DNA fingerprinting in paternity tests and many other applications. By 1986, the terms “DNA profiling” and “DNA typing” were also being used to refer to the technique. In the same year, DNA profiling saw its forensic debut in a murder case in Leicester, Jeffreys’s hometown. This first...
(The entire section is 288 words.)
Postconviction Exonerations (Forensic Science)
The power of DNA evidence to solve crimes and convict perpetrators is widely known, but the general public is perhaps less aware of the potential of such evidence to free wrongfully convicted individuals. The first person in the United States whose criminal conviction was overturned as the result of DNA evidence was a Chicago man named Gary Dotson. He was convicted in 1981 of a rape that never occurred and exonerated in 1989. The purported rape victim had recanted her testimony in 1985, but it was not until 1988 that DNA analysis positively excluded Dotson as the source of semen found on his accuser (the semen was that of the young woman’s boyfriend, with whom she had consensual sex the day she claimed to have been raped). In 1993, Kirk Bloodsworth became the first person in the United States to escape a death sentence as the result of DNA analysis; he had been convicted of the 1984 rape and murder of a child, but postconviction DNA analysis proved that semen found on the victim was not his. The true perpetrator of the crime was eventually identified in 2003, also with the aid of DNA analysis.
Using postconviction DNA analysis to exonerate persons who have been wrongfully convicted is the central mission of the Innocence Project, an organization founded in 1992 by Barry Scheck and Peter Neufeld at the Benjamin N. Cardozo School of Law at Yeshiva University. The Innocence Project provides legal assistance to...
(The entire section is 298 words.)
Regulations Governing Postconviction DNA Testing (Forensic Science)
Although thirty-eight U.S. states have laws in place that allow convicts access to DNA testing, many rules and regulations limit the ways in which postconviction DNA evidence can be used. In most cases, it is typical for states to require that any new evidence be brought to court within six months following a conviction in order to warrant a new trial. In the case of DNA evidence, the drawback of such a rule is obvious: It excludes individuals who were convicted before DNA typing was available but for whom such typing may now provide important evidence relevant to their cases. Since the use of DNA evidence has become commonplace, many states have revised their statutes to allow for the presentation of evidence secured through postconviction DNA analysis even after convicted persons have exhausted all of their appeals.
The Innocence Project has made several suggestions for the improvement of state statutes related to postconviction DNA analysis. The organization asserts that state laws should provide for access to DNA testing wherever it can establish innocence, even in cases in which defendants have pleaded guilty; should set no absolute deadlines on when such access will expire; should provide access to currently available DNA technology, not dependent on whether such technology was available at the time of trial; should allow for flexibility in where and how DNA testing is conducted; should...
(The entire section is 331 words.)
Further Reading (Forensic Science)
Johnson, Paul, and Robin Williams. “Post-conviction DNA Testing: The United Kingdom’s First ’Exoneration’ Case?” Science and Justice 44, no. 2 (2004): 77-82. Examines in detail the first case in England in which postconviction DNA testing was used in a successful appeal by an imprisoned offender.
Kobilinsky, Lawrence F., Thomas F. Liotti, and Jamel Oeser-Sweat. DNA: Forensic and Legal Applications. Hoboken, N.J.: Wiley-Interscience, 2005. Presents a general overview of the uses of DNA analysis.
Lazer, David, ed. DNA and the Criminal Justice System: The Technology of Justice. Cambridge, Mass.: MIT Press, 2004. Thought-provoking collection of essays explores the ethical and procedural issues related to DNA evidence.
Rudin, Norah, and Keith Inman. An Introduction to Forensic DNA Analysis. 2d ed. Boca Raton, Fla.: CRC Press, 2002. Provides a good introduction to the history and application of DNA fingerprinting in forensic investigations.
Scheck, Barry, Peter Neufeld, and Jim Dwyer. Actual Innocence: Five Days to Execution, and Other Dispatches from the Wrongly Convicted. New York: Random House, 2000. Describes some of the most prominent and successful cases taken on by Scheck and Neufeld’s Innocence Project.
(The entire section is 177 words.)