The man killed in a standoff Friday in the wake of shootings that killed five officers expressed anger about recent deaths involving police. Multiple reports identified him as 25-year-old Micah Johnson, based on law enforcement sources.

The suspect, pinned in at a parking garage at El Centro College, spoke with a police negotiator before attempts to get him to surrender broke down, and they exchanged gunfire. Dallas Police Chief David Brown said he was killed by police using an explosive device carried by a robot.

“The suspect said he was upset about Black Lives Matter,” Brown said. “He said he was upset about the recent police shootings. The suspect said he was upset at white people. The suspect said he wanted to kill white people, especially white officers.”

Brown said the man did not claim affiliation with any group and was acting on his own. A representative for the U.S. Army said Johnson had served as an enlisted soldier and did a tour of duty in Afghanistan, according to the Associated Press.

Three others were taken in to custody from the shootings that also left seven other officers and two civilians wounded. The police chief said some of the injured officers had been released from the hospital, and others still needed more treatment.

The suspect threatened that he had placed improvised explosive devices in the area, but police have found no evidence of them.

Brown said Friday that the sniper or snipers fired ambush-style on officers during a protest through downtown and appeared to be trying to kill as many as they could.

“The suspect told our negotiators that the end is coming,” Brown said.

Brent Thompson, 43, with the Dallas Area Rapid Transit Police Department was identified as one of the officers killed. He had been with the department since 2009 and had gotten married to another DART officer just weeks before the shooting.

Three other DART officers, 44-year-old Officer Omar Cannon, 32-year-old Officer Misty McBride and 39-year-old Officer Jesus Retan; had been shot but are expected to recover, a department spokesperson said. Dallas police have not identified the other officers killed or wounded.

Brown credited officers with running toward the gunfire from an elevated position, with no way to protect themselves, in an effort to help get people to safety.

“(They are) some of the bravest men and women you ever want to be associated with,” the police chief said.

The incident was the deadliest attack for police in the U.S. since 9/11.

Dallas police tweeted a picture of a man around 11 p.m., calling him as a suspect in the shootings. The man, who was legally carrying a rifle during the protest, turned himself in, was cleared of suspicion and released by authorities after questioning, according to the Washington Post.

President Barack Obama spoke from Warsaw, Poland, where he was scheduled to be at a NATO summit. He called the attack on law enforcement “despicable.”

“There is no possible justification for these kinds of attacks or any violence against law enforcement,” Obama said. “Anyone involved in the senseless murders will be held fully accountable. Justice will be done.”

The protest in Dallas was one of many across the country in response to two black men killed by police officers this week that were captured on video. Alton Sterling, 37, was killed by officers in Baton Rouge, LA, and Philando Castile, 32, was killed during a traffic stop in Falcon Heights, MN.

– Newschannel 6