On the Case with Paula Zahn (2009)

S7E5 A Knock on the Door

A young mother is discovered dead in her own bedroom, the victim of a brutal murder. The sole witness to the crime is her five-year-old son. Now, detectives must find a way to communicate with the traumatized child, hoping he can provide the crucial clue that will lead them to the killer. Can a preschooler help solve a homicide?