I kill ... I wound ... I will make mine arrows drunk with blood, and my sword shall devour flesh. Deuteronomy 32:39-42
First Kings begins with Solomon murdering Job and Shimei, in accordance with the deathbed wish of his father, David. After that, the killings really get weird.
God sent a lion to kill a prophet for believing another prophet's lie. Then he sent another lion to kill a man for not smiting a prophet. God killed King Ahab for not killing a captured king, and killed 450 losers of a prayer contest with Elijah. He killed 100,000 Syrians for calling him a god of the hills, and 27,000 soldiers by having a wall fall on them.
Because God thought Jeroboam was the worst person in the world (1 Kings 14:9), he killed his son and entire family ("everyone that pissed against the wall"). Then God punished the guy (Baasha) who killed Jeroboam's family -- not by killing Baasha, but by killing all of his wall-pissing family and friends. Finally, Zimri, who killed Baasha's family and friends, burned to death for doing "evil in the sight of the Lord."
Here are the killings in 1 Kings:
