DALLAS (AP) -- Military service changed the Dallas gunman from an extrovert into a hermit, his parents said in an interview excerpt published Monday.
Micah Johnson's mother, Delphine Johnson, told TheBlaze website in an interview published Monday that her son wanted to be a police officer as a child and that his six years in the Army Reserve, including a tour in Afghanistan, were "not what Micah thought it would be ... what he thought the military represented, it just didn't live up to his expectations."
His father, James Johnson said haltingly and through tears: "I don't know what to say to anybody to make anything better. I didn't see it coming."
Micah Johnson, a black 25-year-old who was accused of sexually harassing a female soldier while deployed in Afghanistan, fatally shot five officers in Thursday's attack, which happened while hundreds of people were gathered in downtown Dallas to protest recent fatal police shootings, and wounded at least nine officers and two civilians.
Eleven officers fired at Johnson and two used an explosive device on Thursday night, Dallas Police Chief David Brown said Monday. He noted that the investigation will involve more than 170 hours of body camera footage and "countless hours" of dashcam video. Brown also said that Dallas police are taking all threats seriously in the wake of the shootings.
"Bravery is not a strong enough word to describe what they did that day," Brown said of officers' response to Thursday's events.
Authorities have said Johnson had plans for a larger assault, possessed enough explosive material to inflict far greater harm and kept a journal of combat tactics.
"We're convinced that this suspect had other plans and thought that what he was doing was righteous and believed that he was going to target law enforcement -- make us pay for what he sees as law enforcement's efforts to punish people of color," Brown told CNN's "State of the Union" on Sunday.
Brown also revealed details Sunday about Johnson's negotiations with police, saying he laughed at authorities, sang and at one point asking how many officers he had shot. Johnson insisted on speaking with a black negotiator and wrote in blood on the wall of a parking garage where police cornered and later killed him, Brown said.
The gunman wrote the letters "RB" and other markings, but the meaning was unclear. Investigators are trying to decipher the writing by looking through evidence from Johnson's suburban Dallas home, Brown said.
The writing suggested that Johnson was wounded in a shootout with police. An autopsy will confirm exactly how many times he was hit, Jenkins said.
The fact that Johnson had material for explosives and talked of using homemade bombs during a standoff with police before he was killed indicated he could have inflicted more damage with more time, Dallas County Judge Clay Jenkins said.
"If this had not been a crime of opportunity where the protest was quickly organized in response to events in the same week ... he could have caused a lot more harm than he did," Jenkins said.
The police chief defended the decision to kill Johnson with a bomb delivered by remote-controlled robot, saying negotiations went nowhere and that officers could not approach him without putting themselves in danger. He also said he became increasingly concerned that "at a split second, he would charge us and take out many more before we would kill him."
Johnson's time in the Army was marked by a sexual harassment accusation in May 2014 while in Afghanistan. The Army sent him stateside, recommending an "other than honorable discharge" -- which is "highly unusual" because counseling is usually ordered before more drastic steps are taken, said Bradford Glendening, the military lawyer who represented him.
"In his case, it was apparently so egregious, it was not just the act itself," Glendening told The Associated Press. "I'm sure that this guy was the black sheep of his unit."
According to a court filing, the victim said she wanted Johnson to "receive mental help," and sought a protective order to keep him away from her and her family. Johnson was ordered to avoid all contact with her.
The shootings just a few blocks from where President John F. Kennedy was slain in 1963 marked the deadliest day for U.S. law enforcement since the Sept. 11, 2001, terrorist attacks.
Federal agents are trying to trace the origin of the weapons used, including a military-style semi-automatic rifle. About 30 agents are involved in identifying bullet casings, said William Temple, the Dallas agent in charge for the Bureau of Alcohol, Tobacco, Firearms and Explosives.
The large crime scene includes the parking garage where Johnson was killed and at least two other sites where he is believed to have fired at officers.
The attack began Thursday evening during protests over the police killings of Philando Castile, who was fatally shot near St. Paul, Minnesota, and Alton Sterling, who was shot in Baton Rouge, Louisiana, after being pinned to the pavement by two white officers.
Video from Dallas showed protesters marching along a downtown street about half a mile from City Hall when shots erupted and the crowd scattered, seeking cover.
Among those injured were two officers from El Centro College, the school said in a statement Sunday night, identifying them as Cpl. Bryan Shaw and Officer John Abbott were hurt in Thursday's attack.
Shaw was struck by a bullet as he guarded an entrance to the college, but treated on scene, the statement said. Abbott was also guarding the entrance, and was hurt in both legs from flying glass after it was struck by bullets. Abbott tended to his wounds at the scene and then returned to assist others, the statement said.
Dallas police previously said seven officers and two civilians were hurt in the attack. Its number of wounded did not include any El Centro College officers.
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