During his childhood, Shawn Spencer developed a remarkable talent for noticing the tiniest of details under the guidance of his policeman father. However, upon growing up he found it difficult to get a job, and spends most of his time using his skill to give the police anonymous tips. However, the tips are so good that some cops become suspicious that he is involved with the crimes himself. To clear his name Shawn finally settles on a career: he pretends to be a psychic. No one really believes him, but he continues to be so helpful to the police that they keep calling him in on cases they can't solve. Shawn soon brings his childhood friend Gus into his scheme, and between their bantering they manage to solve every case they're presented with.

The theme song of the series, "I Know, You Know", is performed by The Friendly Indians, the band of series creator, Steve Franks.

Shawn Spencer:
The chips say you're a cheater, cheater pumpkin eater!

Written by Steve Franks
Performed by The Friendly Indians