DALLAS — Details about the now-infamous Dallas shooter have begun pouring out, following his death in a six-hour standoff with police that claimed the lives of five officers at a protest rally downtown.

On July 8, police raided Micah Xavier Johnson’s mother’s house in Mesquite, Texas. There, they found bomb-making materials, ballistic vests, rifles, ammunition, and a personal journal of combat tactics.

He was armed with a SKS semi-automatic rifle and a handgun, and was wearing body armor. During the standoff, Johnson shot 12 police officers and killed five. Two civilians were also shot. Johnson told negotiators he wanted to exterminate whites, especially white officers. The shooting began just before 9 p.m. and ended just past 3 a.m, when police sent in a robot-delivered bomb to finally take him out.

Johnson was a military veteran. He was enlisted in the U.S. Army from March 2009 to April 2015, and served in Afghanistan from November 2013 to July 2014.

Officials have declared Johnson as the lone gunman in the attack. Johnson claimed to be upset over the killings of black men Alton Sterling and Philando Castile at the hands of police earlier this week.