Having been involved in SWAT team training before I got a conscience, got out, and got an honest job:
Every PD SWAT team I worked with was the place where the department concentrated their loose cannons, trigger-happy cowboys, gonzo gung-ho Soldier of Fortune military dress-up queens, anger management nutcases, and einsatzgruppen wannabes. Every one. I did not meet *one* SWAT cop I would trust with a loaded gun if I was standing in front on him, and I met a hell of a lot I wouldn't trust even if I was standing well behind them. The job positively draws guys who salivate at the prospect of smashing things, hurting people, whipping around loaded guns like garden hoses, and opening up a can of whupass on anybody they feel like without fear of any repercussions.
I have heard this "got a conscience and left" on other time and from a personal acquaintance of mine. It struck me as an oddity for a time, but perhaps that is not so.