The Shield: Haunts

New Barn member Kevin tracks down an undercover federal agent who sheds light on the San Marcos murders: it seems the Mexicans and the Salvadorians got into a major battle. This same agent is able to confirm for Vic that Guardo wasn't in the U.S. at the time of Lem's murder, leaving Vic to grapple with the fall-out of murdering him. Meanwhile, Dutch discovers that a social worker is responsible for the serial rapes and that the man was driven to his horrific acts after his own daughter went missing; and, Shane confesses to Mara that he killed Lem after she discovers he's been cheating on her with an underage girl.