TMZ Sports has obtained Richie Incognito's arrest video -- showing cops running up on the NFL lineman after he allegedly threatened to shoot staffers at an Arizona funeral home in the wake of his dad's death.
It all went down on August 20 -- the footage begins with a staffer telling cops Incognito was bullying people in the mortuary and "threatened one of our funeral directors."
When cops entered the place, Richie was already face down on the floor -- and attempting to cooperate with police. But things got very weird a short time later.