DNA is not everything and could be misleading

DNA links Everett man to second cold-case slaying
[Via The Seattle Times: Local News]

A 73-year-old Everett man arrested by Seattle police in connection with a cold-case murder from 1972 was ordered held without bail Friday during a brief hearing that the ailing defendant declined to attend.


DNA’s Dirty Little Secret
[Via Political Animal]

DNA’S DIRTY LITTLE SECRET…. Is DNA evidence, a forensic tool known for exonerating the innocent, being used to put them behind bars? That’s what lawyer and journalist Michael Bobelian argues in the new issue of Washington Monthly. DNA has a…


Too many people think that DNA is total proof. Read the comments to the Seattle Times article. They have already convicted the guy and want him dead.

But read the second article and discover how the statistics they so often use to try and make DNA testing sound so strong can simply fall apart when looking at cold cases where the DNA is the only evidence.

Degraded DNA. Incomplete markers. These rapidly reduce the statistics. If there is a 1 in a million chance of something and you search for it in a database of 10 million people, chances are you will find several matches just by random chance.

So, if they search a database of 333,000, they have a 1 in 3 chance of finding someone just by random. If there is nothing else to put the person at the scene of the crime, should they be convicted by a 1 in 3 chance?

The prosecutor himself said that there were 18 other people in California at the time that would have the same DNA profile. So, if they had a database of everyone in California, they would have had 18 suspects.

Lucky for them they had a much smaller database.

The horrible thing is that the defense lawyers are often prevented from bringing this point up. They also are often not permitted to do independent tests because all of the original sample was used up in the first test.

How in the world can someone be put in prison e=because of faulty statistics, a fact that they are not even allowed to present in their defense.