A former police officer, now a community activist, is a suspect in the murders of known sex offenders, all of whom share a certain characteristic that scars their victims for life. The detectives find it's difficult to protect potential victims when they used to be perps as they investigate the murders of two convicted rapists.

When a pediatrician convicted of abusing patients is found dead, Stabler and Benson investigate and soon find ADA Cabot has a reason for becoming involved in the case.