The level of training required to consistently use a gun in a non-lethal manner is above what almost everyone, including police officers, receives. Most people are trained to shoot for center mass; otherwise you're probably just going to miss.

I sure hope not. Firing to incapacitate isn't that difficult, and most officers will never have to use their guns at all.
It will depend on the calibre of the weapon, if you have a .22, it's not that hard to shoot in a non-lethal manner.
Comment