2 Samuel 4

Ish-bosheth, the son of Saul, is killed through a ruse at the hands of Rechab and Baanah, the sons of Rimmon, the Beerothite. And, when they announced the news to David and showed him the head of his enemy, they were killed by David, who said, "Wicked men have slain a just man in his own house upon his bed." Ish-bosheth was certainly not a just man, and yet he is called a just man because he was innocently killed.