As the gunfire stopped at a parking garage in downtown Dallas, where five police officers were killed and seven others injured in "ambush style" firing during a protest against the fatal police shootings of black men this week, a new trend in crime-fighting crawled into spotlight.
Even as Micah Xavier Johnson, a 25-year-old Army reservist, was executing the deadliest attack on law enforcers in America since 9/11 and threatened negotiators that more officers were going to get hurt, the Dallas police bomb squad deployed a robot that eventually brought the stand-off to an end with a bang.
Without revealing details about the robot, Dallas police Chief David Brown said: "We saw no other option but to use our bomb robot and place a device on its extension for it to detonate where the suspect was. Other options would have exposed our officers to grave danger. The suspect is deceased as a result of detonating the bomb."
Robots are common in police departments, and generally used to disable explosive devices or disorient and incapacitate suspects that are barricaded. To do this, the robot generally carries a flashbang, a device that emits a bright light and loud sound. Sometimes these robots are used to place an explosive near a bomb in order to disarm it via explosion.
But the decision to deliver a bomb by robot stunned former law enforcement officials, who said they believed the new tactic blurred the line between policing and warfare.
"The further we remove the officer from the use of force and the consequences that come with it, the easier it becomes to use that tactic," Rick Nelson, a fellow at the Center for Strategic and International Studies and a former counterterrorism official on the US National Security Council told The New York Times. "It is what we have done with drones in warfare."
"In warfare, your object is to kill," he added. "Law enforcement has a different mission."
According to media reports, the Dallas Police Department owns at least three bomb robots. The vendor for those devices is Remotec, a subsidiary of defence contractor Northrop Grumman Corp that specializes in manufacturing remotely-operated robotic vehicles.
Technology warfare experts said the use of a robot to kill someone had major technological and legal implications for 21st century policing.
"It is a first by police," Peter Singer, author of Wired for War -- a book on the use of robots in conflict zones -- told Reuters.
Singer said that he knew of examples of the US military in Iraq "jury rigging a surveillance bot to take out an insurgent down an alley."
An expert in legal issues and robotics said he thought the use of the robot was justified, and saw little difference between its use and having a sniper shoot from a distance.
"No court would find a legal problem here," said Ryan Calo, professor at the University of Washington law school told The New York Times. "When someone is an ongoing lethal danger, there is not an obligation on the part of officers to put themselves in harm’s way."
Other experts said that the use of a 'robot bomb' sets a worrying precedent about lethal force that is completely separate from the ethical considerations of shooting a gun.
"The legal framework for police use of force assumes human decision-making about immediate human threats," Elizabeth Joh, a professor of law specializing in policing and technology at the University of California Davis, told Huffington Post. "What does that mean when the police are far away from a suspect posing a threat? What does ‘objectively reasonable’ lethal robotic force look like?"
"This seems to be a jury-rigged robot. What happens when a police department buys the first AI police robot capable of lethal force? No clear answers, but the future's already here," Joh said.