Mourners left flowers and prayed at a memorial for the six victims of a school shooting in the U.S. city of Nashville .
Authorities said a heavily-armed 28-year-old fatally shot three children and three adult staffers at the private Christian school, and the assailant was later killed by police.
The suspect, a former student at the school, had drawn detailed maps of the school, including entry points for the building, and left behind a “manifesto” and other writings that investigators were examining, Police Chief John Drake told reporters. The motive was not immediately known.
Last year saw 303 such incidents, the highest of any year in the database, which goes back to 1970.
