It is now being reported that they where ordered not to go in unless their body camera's, which they didn't have, where on.
Virtually everything I have ever read until two days ago (and I used to hand load a lot) indicates that velocity primarily effects accuracy at distance and that bullet construction and size primarily effects "stopping power" (and I apologize for using that phrase in this context, but when discussing hunting loads, that is the phrase used to describe the damage a particular load does to a game animal).
Second, when you get bullets traveling at 3000 fps and over--these days, way over--even the strongest and slowest-expanding of them makes a mess of whatever it hits unless the shot is long enough to let some of the velocity drain off. If you are a trophy hunter and don't mind an acre or so of hamburger around the entrance hole, this is not an objection. But if you like wild meat and are disturbed by the waste of same, it is a problem.
I started out believing devoutly in lots of speed, but 40 years later, having shot creatures of all sizes with just about everything that goes bang, I've never been able to find any correlation between bullet speed and sudden animal demise.
@roycroftmom Perhaps you should read this month's Atlantic magazine, which has the account of a Parkland hospital doctor who treated the casualties. That gun is intended to inflict the maximum amount of damage on the human body by shredding organs at a very rapid rate. He discusses the futility of treating those shot and his frustration.
As I said above, the thing that would scare me the most would be a loon with a shotgun in an enclosed space.
Maybe they hesitated because, oh, you know, they didn't feel like dying on Valentine's Day.
"The wounds are just otherworldly," said Penn Medicine trauma surgeon Jeremy W. Cannon, an expert marksman who served with the Air Force in Iraq and Afghanistan. "You're talking big, giant cavities and a hole you can put your fist through."