Overdue

Dave looked at the dead body and expected a measure of remorse that never materialized. He realized the man's death had been completely warranted.

Murder, in both the legal and moral sense, can at certain times be justified. Self-defense is the most obvious example, but there are also cases of extreme mental and emotional abuse which absolve a murderer of guilt. Warfare allows for the killing of enemy soldiers even when on the losing side.

In this case, the pile of overdue library books stacked high in the corner gave Dave all the reason he needed to kill Mr. O'Leary.