"Glock type pistols seem to have more negligent discharges than other types."
I can think of half a dozen NDs that occurred locally with Glocks over the years, and in all but two incidents it happened when an inexperienced or distracted officer tried to disassemble the gun with a round still in the chamber . . . in the other cases somebody had their finger on the trigger when chambering a round. One shot the wall in the restroom and the other put a round through the window of the office (and then in panic lied about what happened, and got fired).
Some people just shouldn't have guns. And unfortunately, some of the people that shouldn't have guns are cops . . .