Well, that's their motivation and purpose, right? They shot the boat for 15 minutes and couldn't manage to kill him, so now they'll make sure he gets a mistrial and he'll never be seen or heard from again.
That’s a stretch, especially in light of the fact many of those bullits were fake...same with the bang bombs...all met to startle him...
Further they weren’t out to kill him, and that was said the night of the chase many times...they wanted him alive.
....included homemade grenades, a bomb, and at least four guns, ...including two handguns and a BB gun which they used in the Watertown street fight, ....plus an M-4 carbine rifle.......described by the Times as an M-4 carbine rifle ....”similar to ones used by American forces in Afghanistan,”..... was reportedly “FOUND ON THE BOAT” in the Watertown driveway where Dzhokhar was captured. ....It is unclear whether the rifle is a semi-automatic civilian model or the selective-fire model used by the military.
Tsarnaevs allegedly killed an MIT police officer to obtain another handgun. They failed because they couldn't remove the handgun from the slain officer's locking holster. “There was apparently an attempt to yank it and they couldn't get it and left,” reported CBS News
According to the Washington Post, authorities are attempting to trace one of the Tsarnaevs’ handguns, whose serial number was removed. If technicians are able to determine the serial number, they plan to hand it over to the Bureau of Alcohol, Tobacco, Firearms, and Explosives in West Virginia”
Not to be overlooked....there was reason to suspect the guy could be “wired” with a bomb....and why the robot was used to lift the boat hood. Thus live bullits shot by officers were at a minimum.