Mike Donovan was a rich man featured in episode one of the first series, he murdered and presumably raped three children without being punished. Dexter Morgan dug the victims from their graves, where Donovan had hidden them.After kidnapping Donovan by strangulation threats, Dexter showed Mike the decomposing bodies, after Mike had made several excuses to save himself, and said he and Dexter did the same thing, Dexter said he could never kill children. Following this statement, Dexter gave him a dose of something which made him immediately become unconscious and he later woke up on a metal slab, restrained by several layers of shrink wrap. Dexter cut Donovan's cheek and took a drop of blood for his trophy collection , after this he took a small chainsaw-like device and (unseen) decapetated him. Mike Donovan was the first victim the show saw Dexter kill, not chronologically.