On Science: DNA and the Innocence Project
This article first appeared in the St. Louis Beacon, Nov. 18, 2009 - In England, the government collects DNA samples from its citizens with far greater regularity than in this country, claiming that the preserved samples provide law enforcement with a very large database with which to snare suspected criminals and terrorists. In recent weeks, there has been a growing backlash of vocal public objection to the British government's DNA I.D. program as a violation of privacy to which every citizen has a right. This has led to some very public soul searching by government officials and moves by the courts to reign in the scope of the DNA sampling.
With all of this negative talk about DNA profiling, I could not help but reflect on the great power for good that DNA samples also provide. Every person's DNA is uniquely their own, a sequence of nucleotides found in no other person. Like a molecular social security number a billion digits long, the nucleotide sequence of an individual's genes can provide proof-positive identification of a rapist or murderer from DNA left at the scene of a crime -- proof more reliable than fingerprints, more reliable than an eye witness, even more reliable than a confession by the suspect.
Murder of William Beason
Never was this demonstrated more clearly than three years ago in a Rochester, N.Y., courtroom. There a judge freed convicted murderer Douglas Warney after 10 years in prison.
The murder occurred on New Year's Day in 1996. The bloody body of one William Beason, a prominent community activist, was found in his bed. Police called in all the usual suspects, in this case everyone known to be an acquaintance of the victim. Warney, an unemployed 34-year-old who had dropped out of school in the eighth grade, committed robberies, and worked as a male hustler, learned that detectives wanted to speak to him about the killing, and went to the police station for questioning. Within hours he was charged with murder.
Warney's interrogation was not recorded, but it resulted in a signed confession based on the words that the detective sergeant said Warney uttered, a confession that contained accurate details about the murder scene that had not been made public.
Warney said that the victim was wearing a nightgown and had been cooking chicken in a pot, and that the murderer had used a 12-inch serrated knife. The case against him in court rested almost entirely on these vivid details.
Even though Warney recanted his confession at his trial, the accuracy of his confession was damning. The details that Warney provided to the sergeant could have come only from someone who was present at the crime scene.
There were problems with his confession, brought out at trial. Three elements of the signed statement's account of that night were clearly not true.
It said Warney had driven to the victim's house in his brother's car, but his brother did not own a car; it said Warney disposed of his bloody clothes after the stabbing in the garbage can behind the house, but the can, buried in snow from the day of the crime, did not contain bloody clothes; it named a relative of Warney as an accomplice, but that relative was in a secure rehabilitation center on that day.
The most difficult bit of evidence to match to the written confession was blood found at the scene that was not that of the victim. Drops of a second person's blood were found on the floor and on a towel. The difficult bit was that the blood was a different blood type than Warney's.
At trial, prosecutors pointed out that the blood could have come from the accomplice mentioned in the confession, and pounded away on the point that the details in the confession could only have come from first-hand knowledge of the crime.
After a short trial, Douglas Warney was convicted of the murder of William Beason and sentenced to 25 years.
When appeals failed, Warney in 2004 sought help from the Innocence Project, a nonprofit legal clinic that helps identify wrongly convicted individuals and secure their freedom. Set up at the Benjamin N. Cardozo School of Law in New York by lawyers Barry Scheck and Peter Neufeld, the Innocence Project specializes in using DNA technology to establish innocence.
The Innocence Project staff petitioned the court for additional DNA testing using new sensitive DNA probes, arguing that this might disclose evidence that would have resulted in a different verdict. The judge refused, ruling that the possibility that the blood found at the scene of the crime might match that of a criminal already in the state databank was "too speculative and improbable" to warrant the new tests.
Someone in the prosecutor's office must have been persuaded, however. Without notifying Warney's legal team, Project Innocence, or the court, this good Samaritan arranged for new DNA tests on the blood drops found at the crime scene. When compared to the New York State criminal DNA database, they hit a strong match. The blood was that of Eldred Johnson, in prison for slitting his landlady's throat in Utica two weeks before Beason was killed.
When confronted, the prisoner Johnson readily admitted to the stabbing of Beason. He said he was the sole killer and had never met Douglas Warney.
This leaves the interesting question of how Warney's signed confession came to include such accurate information about the crime scene. It now appears he may have been fed critical details about the crime scene by the homicide detective leading the investigation, a Sgt. Gropp. It seems Gropp's partner had stepped out to get some papers when the confession was obtained. Gropp died in March 2006.
DNA testing has become a pillar of the American criminal justice system. It has provided key evidence that has established the guilt of thousands of suspects beyond any reasonable doubt -- and, as you see here, also provided the evidence that our criminal justice system sometimes convicts and sentences innocent people. Over more than a decade, the Innocence Project and other similar efforts have cleared several hundred convicted people, strong proof that wrongful convictions are not isolated or rare events. DNA testing opens a window of hope for the wrongly convicted.
George B. Johnson's "On Science" column looks at scientific issues and explains them in an accessible manner.
Johnson, Ph.D., professor emeritus of Biology at Washington University, has taught biology and genetics to undergraduates for more than 30 years. Also professor of genetics at Washington University’s School of Medicine, Johnson is a student of population genetics and evolution, renowned for his pioneering studies of genetic variability. He has authored more than 50 scientific publications and seven texts.
As the founding director of The Living World, the education center at the St Louis Zoo, from 1987 to 1990, he was responsible for developing innovative high-tech exhibits and new educational programs.