[thaumasiotes]

> Manslaughter can be a mistake or an accident, but if you intentionally aggressively killed someone I'd rather not be walking past you on a street or participating with you in an open market

It is my understanding that if you assault someone intending to injure them and accidentally kill them, that is murder in the second degree, unless they provoked you so much that the position of the law is "they were asking for it" (USA) (http://criminal.findlaw.com/criminal-charges/second-degree-m... , http://criminal.findlaw.com/criminal-charges/voluntary-mansl...). I can see your objection to serial killers, but the hypothetical 2nd-degree-murderer doesn't seem to be much risk unless you like to get into bar fights.

The same resource also points out that if anyone dies (and there's some sort of iffy connection to you) while you're committing a felony of any kind, you're guilty of murder. Robbing 7-11 with your buddy who you didn't realize was armed will get you convicted of murder if he happens to shoot and kill anyone.