While Saul was fighting against the Philistines (1 Samuel 31:1–13), David was busy fighting against the Amalekites to rescue his wives and those of his men (1 Samuel 30:1–31).1 David was thus not involved in the death of Saul in any way.
While Saul was fighting against the Philistines (1 Samuel 31:1–13), David was busy fighting against the Amalekites to rescue his wives and those of his men (1 Samuel 30:1–31).1 David was thus not involved in the death of Saul in any way.
1 After the death of Saul, when David had returned from striking down the Amalekites, David remained two days in Ziklag.