Science and the Death Penalty

In a post on the Sciam (Scientific American) Blog, editor Philip Yam addresses the flaws in the Death Penalty exposed by science.

The most obvious evidence of a flawed system is the exoneration of over 100 death row inmates through DNA testing. But this isn’t the only evidence.

Scientific studies have demonstrated how easily the human brain can manufacture false memories or how memories can evolve over time with new information. This renders eye witness testimony much less than 100% accurate. According to the Innocence Project, out of 130 exonerations demonstrated by DNA, 101, or 78%, had some form of mistaken I.D. as a cause of the conviction.

While Yam doesn’t mention it, even some of what used to be considered highly reliable forensic evidence such as fiber analysis, ballistics analysis and even fingerprinting has been undermined to a greater or lesser extent recently. In the 130 exonerations highlighted at the Innocence Project, 21, or 16%, had mistaken microscopic hair analysis evidence associated with them.

So how the hell can the U.S. still apply the death penalty in the face of so much uncertainty? Let’s be honest about it; it’s called politics.

Polls consistently show support for the death penalty in the U.S. from between 60% to 70% of the adult population and there aren’t too many politicians willing to buck those numbers.

However, in the most interesting part of Yam’s post, he proposes that perhaps pollsters should modify their questions somewhat based upon the demonstrated uncertainty of the system. Rather than asking simply are you for or against the death penalty, the polls should ask would you support the death penalty if 1 in 1,000 executions were of an innocent man? What about if 1 in 100 were of an innocent man? What about 1 in 10?

Yam predicts, and I agree, that if the question were phrased that way support for the death penalty would rapidly dwindle as it does when life in prison without any chance of parole is provided as an alternative to the death penalty.

Most Americans tend to be fair minded individuals. Ignorant, but fair minded, most would probably be shocked to learn how many mistakes have been corrected by DNA and that, depending upon who you believe, anywhere between 1 in 1,000 and 1 in 30 of the executions in the U.S. may have been of people who were innocent of at least the crime for which they were executed.

To quote Philip Yam’s conclusion:

“Science has shown that our death penalty system is deeply flawed. Now the U.S. public needs to see those flaws.”

Amen brother, amen.