"This wasn't an ethical dilemma for me", Brown said.
"We believe that we saved lives by making this decision", Brown said.
Law enforcement agencies across the USA are on guard for threats after the police killings and the Dallas attack. Brown said the robot, which was purchased in 2008 for $151,000, is damaged but still functional.
This item has been corrected to show that nine officers, not 11, were wounded in the shootings.
In taking personal responsibility for approving the plan in the aftermath of Thursday's attack, Brown said he was convinced the gunman would have sought to harm other police officers if he had hesitated to give the go-ahead. "There was quite a bit of rambling in the journal that's hard to decipher", Dallas Police Chief David Brown told CNN.
There were also threats of bombs made by the suspect during the standoff, but Brown said officials did not find any explosives. She and Johnson's father, James, aren't sure exactly what happened, but "the military was not what Micah thought it would be", Delphine says.
The U.S. military has used tactical robots to clear buildings, detonate IEDs and patrol unsafe areas for many years in Iraq and Afghanistan.
He also disclosed that during the negotiations the suspect was only willing to talk to black officers as he continued to mock the police force. He was killed Thursday during a downtown protest march. He was with the transit authority for seven years.
Moving in front of the rally in a black Tahoe 4WD, the attacker stopped when he saw a chance to use "high ground" to target police, he added. He also had visited the websites of the Nation of Islam and the Black Riders Liberation Party - which the Southern Poverty Law Center considers to be hate groups. Monday morning commuters honked in support.
No uniformed police officers are apparent at the protest. Five police were killed and several injured during a shooting in downtown Dallas Thursday night.
"I'd do it again", Brown said.
A Louisiana man was accused of posting a video online showing him in his vehicle behind a police auto, saying he wanted to shoot and kill an officer. "He was truly, truly good", she said. He says "while it's been established that hate speech is protected by the First Amendment, we're talking about people specifically saying on Facebook they want to kill white police officers".
Tom Kelly, a lawyer for Jeronimo Yanez - the officer involved in the fatal shooting - told CNN that the Castile matched the description of a suspect involved in an armed robbery.
"The verified reports and evidence we were getting indicated that there were shooters firing from different locations", Jenkins said.
"We had negotiated with him for about two hours, and he just basically lied to us - playing games, laughing at us, singing, asking how many [officers] did he get and that he wanted to kill some more and that there were bombs there", Brown said, "So there was no progress on the negotiation".
Johnson was killed by a bomb-equipped robot but Brown said before then he sang, laughed at and taunted officers, and said he wanted to "kill white people" in retribution for police killings of black people.
Johnson, who was an Army veteran described as a "loner", reportedly insisted on speaking with a black negotiator and wrote the letters "RB" among other markings in his own blood on the wall of a parking garage. It was the deadliest day for US law enforcement since the September 11, 2001, attacks.