Dallas police say the slain suspect in the killings of five police officers had bomb-making materials, ballistic vests, rifles, ammunition, and a personal journal of combat tactics at his home.

They also say that people they interviewed have described 25-year-old Micah Johnson as a loner.

The department also said in a statement Friday that detectives have interviewed more than 200 members of law enforcement and that “it appears at least 12 officers” fired their weapons when someone opened fired on police Thursday night. It happened during a demonstration to protest the recent killings of black men by police in Louisiana and Minnesota.

Police killed Johnson using a robot-delivered bomb after negotiations failed.

They say detectives are in the processing of analyzing the information contained in the journal.

(AP)