Police robots: Departments lack rules on whether they can kill

"Ryan Calo, who teaches robotics law at the University of Washington, agreed.

"Robots raise special concerns in society," Calo said, pointing to movie depictions of autonomous killer robots and their use in war zones. Law enforcement agencies need to take steps to ensure the public that robots are being used appropriately, he said.

He said the frequent use of robots to kill would go beyond what the country is ready for. "I just cannot imagine in our society right now, that we would tolerate robots that were routinely armed.""