DALLAS (KABC) --The Dallas police chief gave details Monday on their investigation of last week's ambush that left five officers dead and others wounded.
Chief David Brown said detectives were still gathering evidence as there are more than 170 hours of body cam video that must be reviewed, and they are gathering police dashcam videos as well.
Brown said 11 officers fired at the 25-year-old suspected Dallas sniper, Micah Johnson, and two used an explosive device.
"Bravery is not a strong enough word to describe what they did that day," Brown said of officers' response to Thursday's events.
The police chief defended the decision to kill Johnson with a bomb delivered by remote-controlled robot, saying he had "already killed us in a grave way, and officers were in surgery that didn't make it."
"This wasn't an ethical dilemma for me," Brown said. "I'd do it again. I do it again to save our officers lives."
Monday morning, civilian victim Shetamia Taylor told ABC News how the heroic actions of several officers saved her and her sons.
"The officer asked aggressively 'is anybody hit?' and I said 'yes, sir, I am in my leg,' and I mean they went into action. They surrounded us," she said.
Brown also stated dealing with the attack, in addition to regular daily crime, has been "difficult at best."
"What we're doing and what we're trying to accomplish here is above challenging, it is. We're asking cops to do too much in this country, we are, we're just asking us to do too much, every societal failure, we put it off on the cops to solve, not enough mental health funding, let the cop handle it, not enough drug addiction funding, let's give it to the cops."
Authorities have said Johnson had plans for a larger assault, possessed enough explosive material to inflict far greater harm and kept a journal of combat tactics.
Brown also revealed the shooter wrote the letters "RB" in at least two locations at the crime scene. The department was still working to understand what that means.
The Associated Press contributed to this report.