Law & Order: Special Victims Unit - Season 12 Episode 13 : Mask

Debbie Shields comes home to find her partner Ann Jackson being raped by a man wearing a haunting mask. Shields contacts Ann's father to notify him of her critical condition. As detectives Benson and Stabler interrogate Ann's father, Captain Jackson, his sordid past is revealed filled with sexual and alcohol addiction. Jackson's new role as a sex therapist is hindering the detectives from getting the information they need to solve the case and if Jackson won't comply, the detectives are going to have to get creative.