The video of the April 2 incident shows a Tulsa County deputy chase and tackle Eric Harris, 44, who they accuse of trying to sell an illegal gun to an undercover officer.
While the deputy subdues Mr Harris on the ground, a gunshot rings out and a man says, “Oh, I shot him. I’m sorry”.
Authorities have identified the shooter as 73-year-old reserve deputy Robert Bates and say he meant to use his stun gun.
The video was released over the weekend at the request of Mr Harris’ family. They have not commented since its release.