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.

Comments

comments

18 Responses

    • The Forensic Outreach Team

      Hi Olivia,

      Thanks for your comment.

      These cases were not chosen on any specific basis with regard to the nature of the crime – but were all cases where the availability of bodily fluid helped to change or adjust the outcome.

      Reply
  1. Suline van der Merwe

    There was a case in South Africa, about 10 years ago, where my aunt’s best friend was murdered by her boyfriend. The weapon was a hammer given to him by her parents as a birthday present ironically. His DNA was the only DNA present on the hammer and it was left at the scene of the crime where he bashed her head in. His lawyers feigned that the police planted the evidence -how would they even have access to the hammer?- and he got off free and the murderer still has not been convicted. It is true that if someone were to wear latex gloves that their DNA wouldn’t be present on the hammer but no one else had access to the hammer or a motive to kill a student who just finished her BA degree. DNA is one of the few indisputable factors that can link the accused of being present at the crime or used the weapons associated. The only way to dismiss DNA evidence is to have a cunning lawyer that can sway a jury/judge of evidence negligence and planting of evidence and although there are crimes where a certain person is framed; it is difficult to plant their DNA but not impossible. u15180965

    Reply
    • Ben

      If his DNA is the only DNA on the hammer, then that means not even the victims DNA was on the hammer. Either you made a mistake or it is likely it was planted since I imagine it would be difficult to murder someone without their DNA getting on the weapon.

      Reply
  2. Gabriela

    Who was the one who discovered how to use dna forensics and what was the first case they experimented with.

    Reply
    • Douglas Filter

      Hi Gabriela – that seems like it would be a fairly simple Google search – and in so doing, bring up lots of related materials you will enjoy.

      Write back and let us know what you discover. This could be your first referenced post to a scientific online journal!

      Reply
    • Douglas Filter

      Hi Lauren,

      Which people? The people who were accused of crimes they did not commit? The people who did the tests who exonerated them? Please be more specific about who is “dumb’ in your opinion, and tell us why you think so.

      You do realize that the first definition of ‘dumb’ – as an adjective – refers to people who cannot speak because of a physical defect or injury, right? The second definition defines ‘dumb’ as a stupid person, which is possibly why you are using that term, but where are any of the people being described acting in a stupid way?

      Please tell us what you intend to say.

      Thanks

      Reply
  3. Agent Zico

    I was thrilled when I ran into this site. Why I’m cringing right now is the OJ’s case. I think the prosecution and possibly the forensic scientists did a poor job in adhering to rules that govern admissibility of evidence in court. C’mon, DNA linked to a suspect= Jail time. I wouldn’t be so careless.
    Hi

    Reply
  4. Ruth McAlister`

    DNA testing has improved over the years and can include or exclude a person accused of a crime. The Night Stalker is one example of how forensic science can catch a guilty person.

    Reply
  5. yashu chandak

    DNA fingerprinting has been used to solve many cases such as Priyadarshini Mattoo (Santosh Kumar Singh v. State thr. CBI)2, she was a 25-year-old law student who was found raped and murdered at her house in New Delhi in 1996. In the year 2006, the Delhi High Court found Santosh Kumar Singh guilty on both counts of rape and murder. Yet another case is of Naina Sahani murder case (State vs Sushil Sharma)3, Rajiv Gandhi assassination (State through superintendent of police CBI/SIT vs. Nalini and Ors.)4 The infamous Rajiv Gandhi assassination case of 1992 using DNA fingerprinting technology and many more cases are present as example.

    Reply
  6. Jessica

    Can you post your sites where you found these cases? Doing a college paper on blood typing and looking for some real life cases where DNA, particularly blood, played a major role. Thanks!

    Reply
  7. Gideon Furruzca

    I’m doing a report on whether DNA should be used in courtroom trials. I need to find evidence for both sides of the argument. I need reasons why it should be used and why it shouldn’t. Can you give me any suggestions?

    Reply
  8. Chris Halkides

    The Gary Leiterman case (Erin Murphy’s book is one source of information) is one in which probable DNA contamination has put an innocent (if not entirely sympathetic) man behind bars for the rest of his life. I am a great fan of DNA evidence, but there is a dark side.

    Reply
  9. Robert Green

    I’d probably add the case of Joseph Kappen as the first use of e familial searching. Then there’s case of Lynette White in Cardiff which involved an exhoneration (can’t quite recall the name). Then there was Craig Harmon – and the murder of Micheal Little. Any of these of interest – I can dig out some further thoughts

    Reply

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