DALLAS (CBSNewYork/AP) — A robotics expert says Dallas police appear to be the first law enforcement agency to use a robot to kill.

Peter W. Singer, of the New America Foundation, says the killing of a suspect in Thursday night’s fatal shooting of five police officers is the first instance of which he’s aware of a robot being used lethally by police.

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Dallas Police Chief David Brown told reporters that after hours of failed negotiations and in order to not put any officers in harm’s way, his department used a robot to deliver a bomb that killed the suspect.

“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,” Brown said. “Other options would’ve exposed our officers to grave danger.”

Singer said in an email Friday that when he was researching his 2009 book “Wired for War” a U.S. soldier told him troops in Iraq sometimes used MARCbot surveillance robots against insurgents.

As CBS2’s Tony Aiello reported, remote controlled robots have been used by police agencies for decades. The tools were developed by the military and have increasingly advanced capabilities.

“It’s amazing. You look outside my office, there’s a steep stairwell, and there’s robots that can actually climb that stairwell,” retired NYPD veteran, former Yonkers Police Commissioner, Edmund Hartnett said.

As CBS2 has reported, Dallas police used a robot equipped with an explosive device to kill suspect Micah Johnson.

Hartnett said he believes Chief Brown made a tough but necessary call to end last night’s violence.

Chief Brown said overnight negotiations with Johnson broke down and they decided to end the standoff with the robot.

“Place a device on its extension for it to detonate where the suspect was. Other options would have exposed our officers to grave danger,” he said.

Hartnett said it’s possible Brown sought legal advice before giving the order.

He compared it to authorities using a sniper to take out a gunman.

“If you have a shot, take it. In this case the sniper, you’ve replaced the police sniper with a robot,” Hartnett said.

Commissioner Bratton said he supports the decision made in Dallas.

“This was an individual who killed five police officers. Why put more officer’s lives at risk?” he said.

The NYPD has the technology to do the same thing here if necessary.

Some experts have raised concerns about this new method of neutralizing a threat. They’ve called for a full review of the decision to deliver lethal force using a robot. Others said they don’t expect police to use robots like this except in extreme cases.

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