where draw the line?

i don't even know what to make of this story! the guy shots an officer in 1966, and when, years later, the officer dies because of complications that were likely attributed to the his being paralyzed from that shot, the shooter could face murder charges? when does the statute of limitations come to play? and who's to say that if he wasn't shot, he could have been killed earlier in some other way? maybe the shooting and his subsequent paralyzing SAVED his life? not that i really think that, but i feel that re-arresting this guy based on the logic that if the officer wasn't shot he'd still be alive right now is along the same logic as that. where do you draw the line?