Just read your post on Heat and watched the clip, and while the whole clip was pretty horrific, the part that hit me the hardest was…… how in the nine hells did he justify taking that final shot? If the guy so much as twitched- not even deliberately using the girl as a shield, but maybe something happened off to the side- the cop would have wound up shooting a little girl in the head! Is he a sociopath or something?
A little bit. Vincent (Al Pachino) is not entirely stable, and Pachino has since gone on record saying his character was coked up throughout the events of the film, though we see almost no examples of that in this sequence.
So, a couple things worth noting. I didn’t cover the characters’ backstory at all, because it’s mostly irrelevant to an overall critique, however, Vincent is a marine. He mustered out and joined the LAPD, which is used as a point of comparison, because Neil McCauley (De Niro) is also a marine who ended up in prison after mustering out.
It’s very difficult to judge distance in Heat, because the film is shot, almost exclusively using 75-100m telephoto lenses which does very strange things to perspective, but Vincent and Michael (Tom Sizemore) appear to be within 30-50m of one another. At those ranges, someone with marine marksman training, using a reasonably accurate rifle on semi-auto, should be able to hollow out a dime.
You can see Vincent do two things before firing. He adjusts his shooting position, moving the sights into line for a precise shot, and he then holds the shot as Michael turns, to give him the cleanest possible shot. Note that the girl (Yvonne Zima)’s head is the furthest from Michael’s when Vincent fires. (Had Michael continued to turn, their heads would have been closer.) He is firing on someone using a human shield, but he’s doing his best to mitigate the danger to her.
If you really want a full, “use of force,” breakdown on the situation, then @skypig357 would be the person to ask, though, the short answer is that Michael was using the girl as a human shield while firing indiscriminately at civilians and police. He needed to be stopped. Unfortunately, given these specific circumstances, killing the perpetrator is the safest way to do that, for everyone else involved.