She had asked: What is he? A friend or an enemy? The alethiometer answered: He is a murderer. When she saw the answer, she relaxed at once. He could find food, and show her how to reach Oxford, and those were powers that were useful, but he might still have been untrustworthy or cowardly. A murderer was a worthy companion. She felt as safe with him as she'd done with Iorek Byrnison the armoured bear.