David settles in Hebron, and scripture relates who his wives and sons were. Why did so many of them go off the "derech"?

After Avner kills Asael, his brothers Yoav and Avishai want revenge

With Asael the son of Zruia chasing Avner ben Nir, Avner kills Asael with the butt end of his spear...

As Avner is making Ishboshet son of Saul King over Israel, Yoav and his men meet up with them at the pools of Givon

Despite David's efforts to expand his kingdom, Avner ben Ner isn't letting it happen

David and his men leave the underground and move to Hebron, the capital of the tribe of Judah, and David is anointed king by the elders of Yehuda

David's lamentation over Saul and Yonatan

After the Amalekite gives over his version of how Saul died, David grills him and kills him.

While in Ziklag, an Amalekite brings to David the bad tidings about the fall of Am Yisrael

The Philistines abuse King Saul's body, the residents of Yavesh Gilad heroically come to the rescue