Hand weapons for the purposes of civilian self-defense, yes (they wouldn't be "guns" except in the loosest of senses).

"Set phasers to stun" and all that; a nice idea, but way beyond the foreseeable future.

Given how many people's lives would be saved, why do you suppose that we don't have more research into less lethal handguns? Phasers, perhaps not. But there are many other options.