DNA testing on crime scene evidence is considered conclusive, but it was not always so. 30 years ago, this tool was considered too controversial to make a difference in identifying or clearing a suspect.
DNA profiling is the process whereby a string of deoxyribonucleic acid (DNA) is extracted from a cell of an organism, mixed with a ‘restriction enzyme’ which, when processed reveals the blueprint of an individual; ‘instructions’ in each of 23 pairs of chromosomes that dictate physical characteristics, function and individuality, each is completely unique to an individual. DNA signature is duplicated in every cell of a person’s body, including urine, tears or semen, therefore scientifically accurate identification can be made.
1. A twist of fate: the first use in England.
A fifteen year old school girl, Lynda Mann was abducted in Narbourough, England. The next day, her body was discovered raped and murdered. Three years later, another young woman met the same fate near Lynda’s resting place. Richard Buckland was arrested and confessed to the second murder only. An untested technique was applied; ‘genetic fingerprinting’ through DNA analysis. Surprisingly, there was no match in either murder, so the test was repeated. Ultimately, Buckland was proven innocent. As to why he confessed, he claimed he had been pressured by police.
5,500 men from the local area were then tested. Colin Pitchfork persuaded a friend to test in his place, but when he bragged about fooling the investigators, he was overheard and reported. His genetic profile matched the semen samples from both girls, and in 1987 he became the first murderer convicted by DNA.
2. The first US evidentiary hearings.
In 1987, Florida’s Assistant State’s Attorney, Tim Berry began collaborating with forensic director Michael Baird to determine how DNA could be used in identification. After a serial rapist terrorized 23 women in Orlando, Tommie Lee Andrews was caught by two fingerprints left on a victim’s window, identification by a victim in a lineup, and with the same blood type left at each scene.
After two retrials, during which time Baird had been both meticulously processing the DNA evidence and Barry prepared compelling legal briefs, in the final trial Andrews complicity was proven by his DNA, genetic profiling was admitted for the first time, and DNA gained legal precedence.
3. OJ Simpson, fame and misfortune.
The 1995 trial of OJ Simpson for the murder of his ex-wife and her friend resulted in a ‘not guilty’ finding for OJ. Evidence from the scene including the “bloody gloves” and copious amounts of blood left on the bodies was collected. Samples matched OJ’s genetic identity without a doubt. The DNA testing was done not only by the police crime lab, but by two independent labs hired by the defendants. It looked to be a simple road to conviction. And then began the ‘DNA Wars’.
After days of accusations about how the blood was collected and processed, the defense alleged that the samples were tainted, mishandled, switched and subjected to other improprieties while under the police custody. Jurors were then pounded with hours of mind-numbing and confusing expert testimony about the procedures and processes, distracted with racism and accusations of evidence planting and attention focused on corruption in the Los Angeles Police Department. The scientific DNA evidence was all but forgotten.
4. Discovering innocence on Death Row.
Illinois Governor George Ryan applied DNA testing to death row inmates in 1998 and found 13 of the 25 could be exonerated by the results. He immediately put a moratorium in executions. The resulting study recommended 85 ways to prevent the death of innocents, with DNA testing at the core.
In Texas, Roy Criner was sentenced with circumstantial evidence to 99 years for the rape and murder of a 16 year old girl. Years later, he submitted to DNA testing which excluded him from being the contributor of genetic material found on the girl, but he remained in prison because the majority of the appeals judges had no confidence that DNA evidence would have weight over witness testimony. After a reporter found additional evidence that implicated another person, Criner was finally set free.
5. A validation in Texas.
Ricky McGinn was tried for the ghastly rape and murder of a 16 year old Texan girl in 1994. He had been previously accused of murder, rape and molestation. Bloody evidence including a hammer found in his car, and drops of blood on his shoes matched the victim’s type. In 2000, after years on death row, an appeal was made to Governor George W Bush to test DNA on a single pubic hair found in the victim’s vagina. Governor Bush granted a stay of execution based on a brief filed by Barry Scheck, OJ Simpson’s lawyer, and tests were made and verified. The DNA matched McGuinn, and his execution was carried out September 27, 2000.
Your Turn:Do you have any other examples of cases where DNA evidence seemingly or actually did change the entire course of events? Do you think DNA is highly-reliable? Let us know in the comments — we’d love to hear from you.