Find the tree planter and you have the culprit.
Sniper Team 1’s view really was partially hidden by the trees, but I think Sniper Team 2 had a clear view all the time. Video shows that Team 1’s rifles never caused a recoil. They were never fired. Team 1 is not the one that shot Crooks.
Troublesome question: did the on-scene supervisor wait until Crooks had already fired to give the OK for Team 2 to take him out?