I don't trust law-enforcement personnel to begin with, and I'm shocked to see so many so-called "conservatives" here who are such ardent supporters of the concept that an intrusive "nanny state" is an acceptable approach to this problem.
I'm not crazy about trusting them too much either; but I'm less crazy about getting assaulted in a situation where I cannot perforce defend myself to the same degree as the antagonist.
If the government will NOT allow me to be armed in certain situations (planes, trains, etc.) to protect Myself and Mine then they damned well BETTER be doing THAT themselves.
The rest of the time: I'll watch out for myself, defend myself as is necessary, and let the government take care of any subsequent prosecution(s) - I am my own first-responder.