That was one of the revelations while I was researching for Chapter 4 of the book, dealing with unavoidable errors in statistical decision making.
The New York Times took up this very important issue in a recent article. Typically, we think that if someone confesses to a crime, the confession is the strongest evidence possible, and guilt is assured. However, criminologists who have studied this issue discover that innocent people do confess to crimes that they did not commit, and not just mentally challenged people. They believe that other evidence will surface to prove their innocence but juries tend to take confession evidence at face value.
The other shocking thing I learned was that it is legal for the police to tell you you failed a lie detector test even if you have passed it. The police also consider lie detector tests as a tactic to extract a confession (because in most courts, lie detector test results themselves are inadmissible.)
The trouble, as the article points out, is that very rarely are such "false positive" errors uncovered and only after extraordinary effort, and therefore the cost to the decision-maker (law enforcers) of this type of error is quite small. That's why the work of non-profit groups like the Innocence Project is absolutely invaluable.
(Thanks to reader Stephen N. for bringing this article to my attention.)
Your title is misleading, and I don't think it's what you wanted to say.
If one were guilty, it wouldn't be a false confession, would it?
The article says nothing about how likely it is that an innocent person confesses (compared to a guilty person?).
The article still is troubling.
Posted by: Jon Peltier | 09/18/2010 at 08:12 AM
Jon: Good point. The title should just say "Innocence makes one make a false confession". It's a paraphrase of something one of the researchers said that I quoted in the book, and I probably got it half wromg.
The point is that the people who make false confessions often do so because they believe so strongly in their own innocence that they feel there will be other evidence that can rescue them despite making the confession (say when pressured with false lie detector test results).
It is without doubt that there are not too many such cases. Since any statistical decision making system will generate false positives, it is not surprising and unavoidable that such cases exist. Neither here nor in my book do I argue that we should have a system that has no false positives.
I think these articles help us understand the "cost" of such mistakes. It is difficult for us to really feel the pain of such mistakes until it happens to someone close to us, unfortuately. I really want to again commend people like the Innocence Project because they are trying to pick up after the "trade-offs" made by society.
Posted by: Kaiser | 09/18/2010 at 01:32 PM