Dr. Walt Massey

Dr. Walt Massey was the main antagonist of the episode Angels that stayed appearing in the season four of Law and Order SVU.

He was portrayed by Michael Hayden.

History
Massey was the prime suspect in the murder of serial rapist and pedophile Bret Jansen and the sexual abuse of his stepson Shawn, whom he took along with his mother and brother after being abandoned by his biological father.

Massey confessed to killing Jansen who sexually abused his children and one to die while the other escaped. He believed that his sexual relationship with Shawn was consensual and that the boy seduced him, and that he was better than Jansen because he only treated them as sexual objects. After that Massey was arrested for his crime and sentenced to death and executed.