Anyone in Golden Valley who is a fan of crime dramas knows that DNA evidence is a clincher at trial. The prosecutor will discover a hidden speck of evidence on the victim’s body or at the crime scene, rush it to the lab and present the evidence in the courtroom. The defendant’s eyes will fall and the jury will sit back, their minds made up that it had to be the defendant.
Yet that story is not real life. It is true that DNA evidence may make it harder for a criminal defenselawyer to clear his or her client’s name, but just because there is DNA evidence doesn’t mean the case is open and shut.
Take, for example, the story of a millionaire who was the victim of a home invasion. The robbers broke into his mansion, stole a considerable amount, and bound and gagged the owner. Unfortunately, the tape that the robbers used ended up suffocating the millionaire and what would have only been a home invasion case quickly became a murder investigation.
Police thought they had solved the case when they found DNA evidence on the millionaire’s fingernails. Not only that, but the DNA matched someone in their database. Police picked the man up and he was quickly charged with murder.
So, why did this case end with the suspect walking free? The man had been in the hospital the night of the murder and could not have been responsible. It seems the emergency medical technicians who brought him to the hospital inadvertently transported his DNA to the scene of the crime and onto the victim’s fingernails.
While DNA is useful, police, prosecutors and especially juries need to recognize its limits.
Source: The New York Times, “High-Tech, High-Risk Forensics,” Osagie K. Obasogie, July 24, 2013