DALLAS — The dead gunman in the Dallas ambush that left five officers dead has been identified as 25-year-old Micah Xavier Johnson of Mesquite, Texas, law enforcement officials said Friday.

Johnson had no criminal record or known terror ties, a law enforcement official said. Johnson, identified by law enforcement officials as the dead gunman in the Dallas ambush, had served in the U.S. Army Reserve, two U.S. officials said.

A neighbor said police cars are outside the Texas home of Johnson. Wayne Bynoe, the neighbor, said Johnson lived with his mother and “keeps to himself.”

Police used a “bomb robot” to kill Johnson. Seven other police officers were injured along with two civilians.

“We cornered one suspect and we tried to negotiate for several hours,” Dallas police Chief David Brown said during a news conference.

But “negotiations broke down” and turned into “an exchange of gunfire with the suspect.”

Brown said a negotiator spoke with Johnson before he was killed about 2:30 a.m. CDT. Brown said JUohnson was upset “with white people” and with recent police shootings in Minnesota and Louisiana.

“The suspect said we will eventually find the IEDs,” Brown said. “He wanted to kill officers. And he expressed killing white people, killing white officers, he expressed anger for Black Lives Matter.

“We saw no other option than to use our bomb robot and place a device on its extension to detonate where the suspect was. Other options would have exposed our officers to grave danger.”