Everyone should spend a little time reading the F_B_I Uniform Crime Report. Fascinating what you'll find there. For example, ordinary citizens shoot and kill 5 times more criminals than policemen do. While doing so, they also only shoot a third as many innocent bystanders as policemen do. Ergo, we ordinary citizens are 5 times more effective than policemen at law enforcement, and 3 times less dangerous to the public while doing so.
And think about this: a number of years ago, the supreme Court ruled that no policemen can be held accountable for failing to protect someone because THAT IS NOT ONE OF HIS DUTIES. Their duty is to protect property!