This is a video taken by one of the witnesses to the shootout, just lightened up a little in order to be able to see better. It  is purportedly from April 18th, 2013, from the  shootout with police at 62 Laurel Street in Watertown, MA.

Suspects’  Honda can be see to the left and the stolen Mercedes SUV to the right. Dzhokhar Tsarnaev can be seen going through a backpack at the front of the Mercedes.

The driver side door of the Mercedes opens and Tamerlan Tsarnaev comes out, taking three shots at police while running to the front of the car.

Both brothers can be seen using a lighter to try to ignite a bomb.

As the video ends, a return shot from the police can be heard.

Original non-lightened video can be found here

HT: Liveleak