Psych: If You're So Smart, Then Why Are You Dead?

Two teenagers, Shockley and Goddard, come to the Psych office to hire Shawn and Gus for a case. They need help and the police won't take them seriously since they are kids. One of their teachers at the Meitner School for gifted students has killed someone and in two days, he'll kill again. The problem is, they don't know which teacher it is, who he killed or who his next victim will be. When they broke into school late one night to pull a prank, they accidentally hacked into a cell phone call being made from the campus. The only other information they could get is that the killer has a deep voice and a cousin named Muriel.