None. Eighty-five kohanim were murdered by Do'eg (1 Samuel ch.22), not by David. When David had fibbed to Achimelech (1 Samuel ch.21), he was acting properly, since he was in danger from Saul and he told an untruth as a method of self-preservation.
David c omitted two main sins the first was sending Uriah to the
army front so that he would surely be killed. So he then married
Bathsheba and committed adultery.