Joe says what is happening to Michelle reminds him of all the times he and Nash went in firing first and asking questions later. In reality the law is police have to clearly identify themselves at least once; no officer enters a situation and just fires on a suspect and asks questions later in your normal situations. Termination, wrongful death suits, all serious consequences that keep an officer from just going in firing first.
The weapon that the sniper uses is of .50 caliber. The wounds caused by a .50 caliber rifle are far worse than depicted.
When the sniper is opening fire on citizens, a man who is eventually shot is seen running with a blood stain on his pants before he is actually shot. The same man, after being shot, is dragged by Nash behind a vehicle with no visible blood on his pants. The camera then goes back to the sniper to see him shooting his gun, then back to the shooting victim who now has a blood stain on his pants.