K-9 is a 1989 American action-comedy film starring James Belushi and Mel Harris. It was directed by Rod Daniel, written by Steven Siegel and Scott Myers, produced by Lawrence Gordon and Charles Gordon, and released by Universal Pictures.
Belushi plays bad-tempered San Diego police detective Thomas Dooley, who has been tagged for execution by a major international drug dealer named Ken Lyman (played by Kevin Tighe). To help, K-9 Sergeant Brannigan (played by Ed O'Neill) gives Dooley an unorthodox drug-sniffing police dog called "Jerry Lee" (named after rock-and-roll singer Jerry Lee Lewis). The duo attempt to put Lyman behind bars but Dooley quickly learns Jerry Lee is a mischievous smart aleck who works only when and how he wants to. Many of the film's gags revolve around Jerry Lee's playfully destructive episodes.
The film has two direct-to-video sequels, K-911 (1999) and K-9: P.I. (2002). K-9 was released exactly three months before Turner & Hooch (with Tom Hanks), which had a similar plot.