Serial killing, does the reason why one is killing really separate the fact that one is killing dozens upon dozens of other humans?

Some people will see military snipers as soldiers just doing their job. The fact of the matter if they are doing their job, they are killing other humans, lining them up in the crosshairs and pulling the trigger. Is the dead any less dead or the killing any less what it is just because the other person has a gun looking to kill someone, just at the time, not the sniper they never saw? If a person just has a joy shooting people who are not soldiers in another army what makes them actually worse than someone killing in the army. A sniper was actually quoted of saying ”it was the ultimate hunting trip: a man hunting another man who was hunting me. Don’t talk to me about hunting lions or elephants; they don’t fight back with rifles and scopes. I just loved it. I ate it up.” To me it sounds as if he relished stalking humans down and killing them, but reduced them in his mind to prey simply because they were soldiers and had guns. In actuality how does his trill of hunting humans differ from one doing it on civilian streets just to see if they can do it other than one is sanctioned because the government sent him and the other not?