2 Samuel 3:27
27 And when Abner returned to Hebron, Joab took him aside into the midst of the gate to speak with him privately, and there he struck him in the stomach, so that he died, mfor the blood of Asahel his brother.
2 Samuel 3:30
30 So Joab and Abishai his brother killed Abner, because he had put their brother Asahel to death in the battle at Gibeon.