2 Samuel 3:30

So Joab and Abishai his brother slew Abner, because he had killed their brother Asahel at Gibeon in the battle.

2 Samuel 2:19-23

And Asahel pursued after Abner; and in going he turned not to the right hand nor to the left from following Abner.

Proverbs 28:17

A man that is laden with the blood of any person Shall flee unto the pit; let no man stay him.

Acts 28:4

And when the barbarians saw the venomous creature hanging from his hand, they said one to another, No doubt this man is a murderer, whom, though he hath escaped from the sea, yet Justice hath not suffered to live.

Treasury of Scripture Knowledge

Summary

So Joab and Abishai his brother slew Abner, because he had slain their brother Asahel at Gibeon in the battle.

Because

Bible References

Slew abner

Proverbs 28:17
A man that is laden with the blood of any person Shall flee unto the pit; let no man stay him.
Acts 28:4
And when the barbarians saw the venomous creature hanging from his hand, they said one to another, No doubt this man is a murderer, whom, though he hath escaped from the sea, yet Justice hath not suffered to live.

Because

2 Samuel 2:19
And Asahel pursued after Abner; and in going he turned not to the right hand nor to the left from following Abner.

American Standard Version Public Domain