Authorities have confirmed that the shooter at the Dallas protest on Thursday acted alone.
Initial reports indicated there could be multiple gunmen, but officials now say 25-year-old Micah Johnson was the only suspected shooter.
"The suspect stated he wanted to kill white people, especially white officers," said Dallas Police Chief David Brown.
Authorities announced Friday morning they killed the suspect by rigging an explosive device to a robot.
They also said that he was a U.S. Army Reserve veteran and served a tour in Afghanistan but was sent home after being accused of sexual harassment.
When police searched the shooter's home, they found bomb-making materials, ballistic vests, rifles, ammunition and a personal journal of combat tactics.
Five officers were killed and seven were injured in the shooting. Two civilians were also hurt.
The shooting came as a rally protesting the police shootings of black men in Minnesota and Louisiana earlier this week wound down. According to local media, gunshots rang out downtown at about 9 p.m. local time.
"Gunfights like the wild, wild West. Police officers started shooting in one direction. They don't know where they're shooting, but they start shooting, and whoever was shooting started shooting back," one witness told KXAS.
It was the greatest loss of life of law enforcement personnel since 9/11, when 72 officers lost their lives.