'Murderer' in the Bible

Now Elisha was sitting in his house, and the elders were sitting with him. And the king sent a man from his presence; but before the messenger came to him, he said to the elders, “Do you see how this son of a murderer has sent to take away my head? Look, when the messenger comes, shut the door and hold the door shut against him. Is not the sound of his master’s feet behind him?”

As Jehu entered the gate, she said, “Is it well, Zimri, your master’s murderer?”