Statistically, combat veterans are 6 percentage points more likely to shoot than non-veterans. (32% versus 26% have discharged their service firearm while on duty, other than at a gun range or during training.)
That stat doesn't mean much to me though. I'd want to know about unjustified discharging of weapons. I'd imagine cities like LA, Baltimore, Detroit, etc are more likely to assign combat veterans to the places with higher crime, particularly gun violence, than anyone else on the force. I'd also expect former military to be involved in S.W.A.T. more than non-veterans. And for that reason I expect their likelihood of discharging a weapon to be higher.
https://www.pewresearch.org/fact-tank/2017/02/08/a-closer-lo...