Pinned to the ground by officers who kneed and struck him, Lawrence Crosby screamed whatever he could think of to convince them that he was a law-abiding PhD student, not a violent car thief.

"This is my vehicle, sir," he said, his voice captured by the dashboard-camera video in October 2015. "I have evidence . . . I purchased this vehicle January 23, 2015, from Libertyville Chevrolet."

Lawrence Crosby is seen surrendering to police shortly before he was crash tackled by several policemen. Credit:Evanston Police Department

It wasn't enough. The officers placed him in handcuffs in the driveway of a church, two blocks from the police station in Evanston, Illinois.

Police released the dash-cam video earlier this week, detailing the half-hour encounter that sparked a civil suit from Crosby and a discussion about race and policing in this city of 75,000, just north of Chicago.