Charlie Cullen is a serial killer, responsible for perhaps as many as 400 deaths. He became known in the press as The Angel of Death when his crimes were finally revealed. He worked as a nurse in several different hospitals in New Jersey and Pennsylvania where he would poison patients by injecting drugs into their IV lines. This fascinating story begins slow. It spends a lot of time detailing how Charlie killed again and again without consequences besides being fired and shuffled off to another hospital to start killing again. The book becomes very frustrating and disappointing until Part II, when the police become involved. The book makes clear how difficult such cases are to investigate and prove, and it clearly identifies some good guys and bad guys. It will make you never want to set foot in a hospital again.