First of all here is the definition of murder. "The unlawful premeditated killing of one human being by another." If the officer shot Armando Walker in this altercation they would have been within their right. They tasered this dirt bag multiple times and that did not stop him. It took backup and the help of a citizen to stop the guy. With all of that said I doubt the officer thought he need to have his gun out when he arrived and then the situation escalated. If they had know Walker had already stabbed a woman I think they would have handle this much differently.