It wouldn't go down to zero, but I think a step up from a taser wouldn't be a bad idea. A taser rifle capable of more consecutive shots, longer and higher velocity prongs for punching through thicker clothing and, higher voltage for those rare few who seem to shrug off normal taser voltages. I bet you could design a heavy duty taser like that to fit as an under barrel attachment so the officer wouldn't lose access to lethal options either.