The Listener (2009) - 1x09 - Inside the Man

When Toby and Oz are called to a crime scene, they discover two dead bodies, Wade and Wendy Lassiter, lying in their own blood. Toby notices there's someone else in the house and the son of the Lassiters is found, hiding, injured and very confused; Toby doesn't really understand the thoughts of this boy.
Charlie Marks leads the investigation, but the only living witness isn't able to talk. She asks Toby for help and they find out this boy has a very rare way of thinking.