Police: Dallas shooter had plans for larger attack July 11, 2016Dallas Police Chief David Brown. (AP/ Tony Gutierrez)(AP/ Tony Gutierrez)Police: Dallas shooter had plans for larger attackMicah Johnson had material for explosives and talked of using homemade bombs during a standoff with police before he was killed, indicating he could have inflicted more damage with more time.The gunman in the deadly attack on Dallas police had plans for a larger assault and possessed enough explosive material to inflict far greater harm, the city’s police chief and top elected official said.Micah Johnson, a black Army veteran, began firing on officers while hundreds of people were gathered in downtown Dallas to protest recent fatal police shootings. Authorities have said the 25-year-old kept a journal of combat tactics and had amassed a personal arsenal at his home that included bomb-making materials.“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,” Dallas Police Chief David Brown told CNN‘s “State of the Union” Sunday.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, said Dallas County Judge Clay Jenkins.“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.Five officers were fatally shot in the attacks, and at least nine officers and two civilians were wounded.New Details RevealedAlso Sunday, Brown revealed new details about Johnson’s negotiations with police, saying that Johnson taunted authorities, laughing at them, singing and at one point asking how many officers he had shot.Johnson, who served in the Army Reserve for six years starting and did one tour in Afghanistan, 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.Dallas shooter Micah Johnson. (Facebook via AP)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.Authorities do not “have any independent report from an officer saying, ‘I think I hit him,'” Jenkins said.The shootings just a few blocks from where President John F. Kennedy was slain in 1963 marked the deadliest day for US law enforcement since the Sept. 11, 2001, terrorist attacks.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 Louisiana after being pinned to the pavement by two white officers.Video showed protesters marching along a downtown street about half a mile from City Hall when shots erupted and the crowd scattered, seeking cover.By: AP DallasDavid Brown