ST. PAUL, Minn. (AP) — A Minnesota prosecutor says he won't bring charges against a St. Paul police officer who shot and killed a man who charged him with a knife.

The shooting came just seconds after 31-year-old Ronald Davis rear-ended Officer Steven Mattson's squad car in the city's Midway neighborhood in September. Ramsey County Attorney John Choi wrote Thursday that Mattson was justified in using deadly force, and his body-camera video proved it.

Police released the video two weeks after the shooting, which sparked a protest to call for an end to police shootings.

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