INTRODUCTION
DNA was discovered in 1868, at about the same time that the Austrian monk Gregor Mendel formulated the laws of heredity, which laid the foundation for the modern science of genetics. A major breakthrough which eventually made possible forensic uses of DNA occurred in the early 1950s when James Watson and Francis Crick solved the puzzle of DNA's structure and precipitated the revolution in molecular biology which followed.
The Bio-Technology Revolution plays a major and ever-expanding role in our life. Medical genetics and gene therapy already have given us tremendous tools to diagnose and treat inherited diseases. With DNA, parentage testing has become a virtually certain procedure. We use DNA to improve animal and vegetable foodstocks, protect endangered species, verify animal pedigrees, detect war crimes and identify human remains. Many POW-MIA families have had the satisfaction of finally learning the fate of their loved ones through DNA testing of bones recovered in Viet Nam. DNA testing was used to make sure that the correct remains were returned to families following the war with Iraq. After the inferno at the Branch Davidian complex in Waco, Texas, DNA was the only way to confirm identities from many of the charred remains.
Our knowledge of the past is considerably strengthened by anthropological and paleontological DNA testing. While Jurassic Park-style reincarnations are fantasy, DNA has been extracted from such remnants of ancient life as fossils, prehistoric bones, and mummies. In the past year, Scotland Yard analyzed a skull fragment and confirmed the identity of Russia's last czar. Ironically, a few months later, a contemporary pretender to the Romanoff name and fortune was unmasked by DNA testing. While these are notable uses of the tests, many people believe DNA's most fascinating use is in criminal identification. Certainly no methodology to emerge thus far from the Bio-Technology Revolution has had a greater impact on the public.
The basic techniques of DNA typing were developed and proven in research and medical laboratories long before they were used in the crime lab. But as we try to reach a fair and just result in the trial of O.J. Simpson, where DNA evidence plays such a prominent role, and as we evaluate the use of DNA testing in the criminal justice system, it helps to remember that the first use of DNA in an American courtroom occurred only seven short years ago.
Since forensic DNA testing was introduced in 1986, it already has been used in approximately 50,000 criminal investigations in the U.S. alone. DNA evidence is most often found in sexual assaults. About three-fourths of the DNA evidence examined by the FBI and other labs consists of semen specimens. About a third of all FBI tests exonerate wrongfully accused men. A quarter of the tests are inconclusive, and about 40% match the suspect's profile.
Most of the DNA casework is performed in 50 or so federal, state and local police crime laboratories (approximately 300 are found throughout the U.S.). As a result, DNA testing is often regarded as a prosecution tool. Certainly, when DNA is used in court and reported in the media it almost always is being used to prove the prosecutor's case. However, it is important to remember that thousands of tests are performed annually which eliminate innocent persons as suspects.
There also are now almost a score of cases in which DNA testing has been used to free previously convicted and incarcerated individuals, some of whom have been in prison for up to twelve years. Another advantage of DNA typing is that it leads to considerable savings in the criminal justice system because suspects confronted with DNA evidence often will plead guilty, thereby saving the considerable costs of a trial.
DNA evidence is a powerful tool for justice to be used by both the prosecution and the defense to benefit us all. |
