The shooting of an elementary teacher by a 6-year-old student in Newport News, Va., last year was preceded by a “shocking” series of lapses by the school’s assistant principal at the time, according to a report by a special grand jury that was released on Wednesday.

Despite having been told that same day that the student was “in a violent mood,” and having received several reports that he was carrying a firearm, the assistant principal turned down a school counselor’s request for…