Psych (2006)

S1E9 Forget Me Not

Henry’s former captain is convinced he’s cracked a murder case, but his Alzheimer’s has left him unable to recall crucial details: the crime itself and the identity of the perpetrator. In response, Henry enlists Shawn and Gus to help unravel the mystery of a murder that occurred many years earlier, relying solely on the captain’s unreliable memories as their only lead to solve the case.