From 1987 to 2003 nurse Charlie Cullen worked at nine hospitals in New Jersey and Pennsylvania. He wasn’t particularly smart or sneaky, he wasn’t a master criminal. But he killed and killed and killed. And every time a hospital became suspicious and let him go, he’d go down the road to another one, get a  job and kill some more. Estimates are he may have killed as many as 400 people before he was finally stopped. Join us in our discussion of the man who may be the most  prolific serial killer in the U.S.