Bruce Jenner -- Video Shows Bruce Squarely to Blame in 'Violent' Crash

Bruce Jenner was squarely at fault in the fatal car crash ... so claim people familiar with the MTA video of the crash.

Law enforcement would not comment on the video, however, others familiar with it tell TMZ it shows the drivers of the other 3 vehicles in the crash did nothing wrong. We're told the video shows the Lexus and the Prius moving at a very slow rate of speed, though it's unclear whether they are accelerating or decelerating. They were in the back of a line of cars stopped for a red light.

As we reported, Bruce told cops at the scene the Lexus driver slammed on her brakes without warning, making it impossible for him to react in time to avoid the crash. We're told the video actually shows the Lexus barely moving -- she did not slam on her brakes -- and Bruce is clearly inattentive, holding his cigarette with one hand and not aware of the traffic in front of him. By the time he realizes he's in peril, he slams on the brakes but it's too late.

We're told the video shows Bruce hit the Lexus "violently" ... rocketing it into the Hummer, killing the Lexus driver. Our sources say the video shows Bruce was clearly traveling at a significant speed given the magnitude of the crash, although cops believe he was not speeding.

Bruce then continued on and hit the Prius, and we're told that collision occurred at almost the exact time the Lexus hit the Hummer, which is why witnesses say they only heard 2 crashes.