The angels of God would never murder, or they would cease from being the an angel of God. The story you read was more than likely a fabrication.

Yes, it's true; the angels of God have helped protect God's people, and these accounts are in the bible. But angels of God do not murder. Only Lucifer and his band of fallen angels would ever be willing to do such a thing. Angels of God strictly do the will of God, and nothing more.