Steven Crawford, David Gladden and Barry Laughman have a terrible thing in common. The three midstate men all were sent to prison on murder convictions, only to have those convictions voided after they spent years behind bars. Prosecutors and defense attorneys have long debated how often the wrong people are convicted and jailed. That argument will have a new framework when two prominent law schools unveil their National Registry of Exonerations today. Officials at the University of Michigan Law School and the Center on Wrongful Convictions at Northwestern University claim the registry is the most comprehensive of its kind. It lists more than 2,000 people that its authors claim were exonerated after being falsely convicted of crimes in the U.S. in the last 23 years.