Soft-tipped bullets have been developed that, rather than killing the victim on impact, instead explode in a cloud of laughing gas. So instead of dealing with a bunch of people with gunshot wounds, you've got a whole bunch of people that are too drugged-up to be a threat anymore. Seems like a good idea, at least at first.
But what about drug addicts that just want a taste of that sweet, sweet gas? Then you'll have people committing crimes and actually wanting to be shot, at least shot by the laughing gas bullets. And there's be a big black market for the bullets, too, with people buying them and shooting them at each other in order to get high. Hasn't this war on drugs taken enough of a toll?