Just pointing out one of the many many times some common sense would have helped in harry potter
John was proud to be a muggle-born while the idiots born into magical world were off hiding, meekly bowing down to the new rule or out right helping it the 5 of them were planning the best way to fight Voldemort that did not involve waiting for the "chosen one" do it for them. John had meet Harry and knew his test scores and work ethic... or lack there of. The only way Harry was taking down voldy was if god herself set up the most unbelievable run of luck and a "deus ex machina" to make him the hero.
He was pulled out of his rant at the stupidity of wizards by Jane's report and the latest news from diagon ally, "Wait! your saying that if we say you-know-who's name his men will show up and attack?"
I have an idea.
At 1am he was standing in a dark forest with night vision goggles ready to begin the plan while the others waited hidden in the area around him.
VOLDEMORT! rang through the still night followed near instantly by the crack of john apparating away.
In no time a half dozen idiots were calling for him to come out with lit wands before a short burst of machine-gun fire took them down before they could even think of a spell.
5 minutes later they had looted the bodies and apparated to a different place to repeat the process.
3 days, 200+ lives, five inner circle members later and still not knowing who was doing it or how (he didn't know any spells that shot bits of metal at people) Voldemort admitted the taboo might have been a mistake.
Not a good story I just wanted to point out that there were a lot more ways to fight voldy then waiting for an (average at best) boy wizard to do it for you.
As for the death toll and how they keep getting away with it, in the time it takes to cast the killing curse they could be shot a dozen times and while the death eaters arrival makes a lot of noise and have to light up their wands to see, the muggleborns are already well hidden with night vision goggles to see and shooting bullets with the guns flashes hidden by a spell compared to the bright flashes of spells they had no idea what they were been hit with or from where.
the inner circle members were sent to kill whoever was responsible by voldy and got killed the same way.
Anyway I hope that makes everything clear and you can understand my point I'm thinking of doing another to show how easy it would be to kill voldy.