In chapter 22, Saul is off the rails! He finds out that the priests of Nob helped David by giving him food and a weapon (Goliath's spear). They also inquired of the Lord on his behalf. This enrages Saul, so he has one of his men (Doeg) kill 85 of them! 

David is distraught when he hears this news and takes full responsibility for the death of the men. 

I wonder if this is why he was a man after God's own heart. He didn't shift the blame. He owned it.

Corporate Soft by LesFM | https://lesfm.net/positive-background-music/ 

Sovereign by Kevin MacLeod | https://incompetech.com/