Men with AR-15s at the core of deadliest mass shooting in U.S.A

Aurora: AR-15
Orlando: AR-15
Parkland: AR-15
Las Vegas: AR-15
Sandy Hook: AR-15
Umpqua CC: AR-15
Waffle House: AR-15
Texas Church: AR-15
San Bernardino: AR-15
Tree of Life Synagogue: AR-15