This is the Cato Daily Podcast for Thursday, September 22nd, 2011.

I'm Caleb Brown.

Prosecutors typically have immunity when they fail to do one of their constitutional duties that is

turning over exculpatory evidence to the defense and failing to turn that evidence

over can mean the difference between winning and losing big cases.

David Ritgers, legal policy analyst at the Cato Institute,

talks about the Supreme Court case of Connick v. Thompson

and his related article in the latest edition of the Cato Supreme Court review.

In 1985, John Thompson was tried and convicted by the New Orleans District Attorney's Office

for both armed robbery and murder.

These were actually wrongful convictions.

The armed robbery case, there was a piece of evidence associated with the armed robbery case.

It was a swatch of clothing stained with the robber's blood.

The prosecution had this piece of evidence and the blood test results, the blood

typing results came back and the prosecutor had the evidence and on the day of trial checked all of the evidence out of the evidence and on the

police evidence room and then checked all of the evidence with the exception

of this

blood-stained swatch of clothing into the courthouse evidence room.

And without this piece of clothing,

which had it been tested and had it been provided to the jury

would have shown that he had a different blood type than the perpetrator of the crime

well he would have been exonerated had that been produced to the jury it was not

...