Statistics and the law

[Outsider]

Lucia de Berk, a Dutch nurse who served more than six years of a life sentence for murdering seven patients under her care, has been fully exonerated. The country's attorney general personally apologised for her ordeal.

This article describes the case:

http://www.guardian.co.uk/commentisfree ... nurse-case

The Lucia de Berk case, like the Sally Clark case, is not just an example of bad statistics, it is also an example of statistical evidence being misunderstood by criminal justice professionals and juries.

These cases, like the Shirley McKie case, relied on expert testimony as the only evidence that a crime occurred as well as indentifying the perpetrator. If my experience over the last couple of years is anything to go by, criminal justice professionals have no idea how risky this is - or even why it is risky.

If fingerprint evidence is one day going to be presented in probabilistic or likelihood terms, somebody is going to have to find a way to explain to the people who use it how it should be interpreted (and how to account for the fact that experts can be wrong). This is most important when there is very little other evidence against the accused.

[Neville]

Hi Steve
No argument there, seems like no argument from anyone on that one.
I would rather argue about a fingerprint identification on the back of my fingerprint knowledge than on statisics any day, I am sure that there some people out there that think some computer will spit out some stats (which it will) then they will take that to court and that proves the ident. Boy are they in for a shock, Who the h..l do they think they are kidding, only themselves! Who is going to give evidence on how that computer came up with those stats, the programmer? which one? they will be busy.

Of course with stats you have to say that this ident maybe someone elses to get a stat, just like you have to say the sun may rise in the west tomorrow if you are wanting stats on the likely hood of the sun coming up in the east tomorrow.

Sorry i just could not do that. You are welcome to that world of fingerprint identification.