2 Samuel 3:27

3:27 When Abner returned to Hebron, Joab took him aside at the gate as if to speak privately with him. Joab then stabbed him in the abdomen and killed him, avenging the shed blood of his brother Asahel.

2 Samuel 3:37

3:37 All the people and all Israel realized on that day that the killing of Abner son of Ner was not done at the king’s instigation.