Friday, May 08, 2009

Confirmation Bias

I read an article from the Wisconsin Law Review, "The Multiple Dimensions of Tunnel Vision in Criminal Cases," by Keith A. Findley and Michael S. Scott, both Professors at the Wisconsin School of Law. "Tunnel Vision," also referred to as "Confirmation Bias," has long been recognized as a cognitive phenomenon, but only recently has its role in wrongful convictions surfaced in popular awareness. A short clip from the prime time TV series Bones, dramatizes a forensic analyst displaying confirmation bias:

Of course a 23 second clip can't begin to tell us all we should know about confirmation bias, but Findley and Scott's article can take us deep into the topic. They describe several cases, including the famous Central Park Jogger case where confirmation bias resulted in wrongful convictions. Then they go on to describe how even trial and appellate judges can become victims of the phenomenon.

Findley and Scott's work is especially meaningful for us because our son Todd's case bears the hallmarks of confirmation bias: an early snap decision by investigators and prosecutors followed by an unwillingness to follow leads that pointed away from Todd as the perpetrator. Prosecutor Amy Mullaney insisted on cutting a plea bargain with the only person seen fighting with the victim, many months before the state's forensic analysis would be complete.

The state even declined to test a blood stain on Todd's jacket. We had it tested at our own expense to prove that the blood did not belong to the victim but rather to Todd. During the appeal, the Deputy Attorney General referred to Todd's blood stained jacket in an attempt to imply that the stain connected Todd to the victim, even though by then the DNA results were in and the stain had been identified as Todd's, not the victim's.

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