The sniper who killed five Dallas police officers Thursday night was a former Army reservist who posted “black power” images online and told police negotiators in the moments before his death he “wanted to kill white people.”

As the law enforcement community reeled from its deadliest day since 9/11, a troubling portrait emerged of Micah Xavier Johnson, 25, who was blown up by a police robot early Friday morning. One friend who served in his platoon during a tour in Afghanistan said Johnson changed after he came home.

Johnson, who is believed to be from the Dallas suburb of Mesquite, confirmed his racial rage to police as he was holed up in the El Centro College parking garage in downtown Dallas.

“The suspect said he was upset about Black Lives Matter,” Dallas Police Chief David Brown said Friday morning. “He was upset about recent police shootings. He was upset with white people.

“He wanted to kill white people, especially white police officers,” Brown added. “The suspect said he was upset at white people.”

Johnson, who wore a dashiki and held a fist aloft on his Facebook page, had a temper and owned “a lot of guns,” according to the friend.

“He did have some anger issues but never said he would hurt anyone,” the friend said, adding with distrubing irony, “His shots were terrible.”

According to a senior U.S. defense official, Johnson enlisted in the U.S. Army reserves in 2009 and rose to the rank of private first class. He had one deployment to Afghanistan from November, 2013 to July of 2014. Upon returning, he remained an inactive reserve until May, 2015, when he was honorably discharged.

“He was absolutely normal, a really good friend. We lost touch once he deployed to Afghanistan and I stayed back,” the friend told “I don’t really know how or why it got to the point it did.”

Although Black Lives Matter protests held around the nation in reaction to racially charged incidents involving police have at times featured calls for killing cops, the movement immediately condemned Johnson’s attack.

“Black Lives Matter advocates dignity, justice and freedom. Not murder,” the group tweeted early Friday.

Fox News’ Jennifer Griffin and Cristina Corbin contributed to this report