'Murderer' in the Bible

But Elisha sat in his house, and the elders sat with him; and the king sent a man from before him: but ere the messenger came to him, he said to the elders, See ye how this son of a murderer hath sent to take away mine head? look, when the messenger cometh, shut the door, and hold him fast at the door: is not the sound of his master's feet behind him?

And when Jehu came in at the gate, she said, Is it peace, Zimri, murderer of his master?