Law & Order: Special Victims Unit S09E04 - Savant

Ben Nicholson finds his wife Corrine beaten into a coma, and the only witness is their mentally challenged daughter, Katie. Because of Katie's sensitive mental condition - the detectives are reluctant to have her testify. Detectives Olivia Benson, Elliot Stabler and Dr. Huang work with Katie, and begin to piece together the night of the beating and some of Corrine's well-hidden secrets.