Professionals are great if you're in a situation that takes long enough to develop for them to arrive. Most crimes don't work that way though.
Our big local story this week was a
Pizza Hut driver who shot an attacker. He was sent to a fake address where four guys waited for him to rob him. He tried to run, they chased him, he shot and killed one. The other three ran and have since been caught. I'm hoping in the end they get charged with the guy's death as the law does indeed allow since somebody was killed during the commission of a crime they were committing, but either way strong-arm robbery and criminal conspiracy is a pretty long stretch.
He didn't want to shoot anyone, he feels terrible about it, but the bottom line is a firearm quite possibly saved his life and got four people who clearly didn't mind preying on the helpless off the streets. The professionals did a bang-up job of finding the other criminals after the fact, but it wouldn't have prevented the driver from being a fish in a barrel. A .45 did.