Law & Order: Special Victims Unit S11E18 - Bedtime

Detective Olivia Benson and Detective Eliot Stabler are called to the scene of a crime where an investigative journalist has been found dead in her bed with an "X" carved into her cheek. Captain Donald Cragen recognizes the killer's tactics from a similar case thirty years earlier, when the "Bedtime Butcher" murdered five women in the Bronx. The trail leads the detectives to a patrol cop, a jealous ex-lover of the prime suspect, and even sends Benson on a dangerous undercover mission to uncover the truth.