Murderer
Even if a guy tested positive for the coronavirus and was terminally ill with it, kneeling on his neck will still cause premature death, death before he was meant to die. Even if he was a guy who did drugs and other things nobody would be proud of.
Killing a drug addict or an ex drug addict would make somebody as much a murderer as killing somebody who never touched drugs and was thought to be clean, pure and wholesome by many people.
By Solid Mantis