"Here is a list of mass shootings in the U.S. that featured AR-15-style rifles during the last 35 years, courtesy of the Stanford Geospatial Center and Stanford Libraries and USA TODAY research: Feb. 24, 1984: Tyrone Mitchell, 28, used an AR-15, a Stoeger 12-gauge shotgun and a Winchester 12-gauge shotgun to kill two and wound 12 at 49th Street Elementary School in Los Angeles before killing himself. Oct. 7, 2007: Tyler Peterson, 20, used an AR-15 to kill six and injure one at an apartment in Crandon, Wis., before killing himself. June 20, 2012: James Eagan Holmes, 24, used an AR-15-style .223-caliber Smith and Wesson rifle with a 100-round magazine, a 12-gauge Remington shotgun and two .40-caliber Glock semi-automatic pistols to kill 12 and injure 58 at a movie theater in Aurora, Colo. Dec. 14, 2012: Adam Lanza, 20, used an AR-15-style rifle, a .223-caliber Bushmaster, to kill 27 people — his mother, 20 students and six teachers — in Newtown, Conn., before killing himself. June 7, 2013: John Zawahri, 23, used an AR-15-style .223-caliber rifle and a .44-caliber Remington revolver to kill five and injure three at a home in Santa Monica, Calif., before he was killed. March 19, 2015: Justin Fowler, 24, used an AR-15 to kill one and injure two on a street in Little Water, N.M., before he was killed. May 31, 2015: Jeffrey Scott Pitts, 36, used an AR-15 and .45-caliber handgun to kill two and injure two at a store in Conyers, Ga., before he was killed. Oct. 31, 2015: Noah Jacob Harpham, 33, used an AR-15, a .357-caliber revolver and a 9mm semi-automatic pistol to kill three on a street in Colorado Springs, Colo., before he was killed. Dec. 2, 2015: Syed Rizwyan Farook and Tashfeen Malik, 28 and 27, used two AR-15-style, .223-caliber Remington rifles and two 9 mm handguns to kill 14 and injure 21 at his workplace in San Bernardino, Calif., before they were killed. June 12, 2016: Omar Mateen, 29, used an AR-15 style rifle (a Sig Sauer MCX), and a 9mm Glock semi-automatic pistol to kill 49 people and injure 50 at an Orlando nightclub before he was killed. Oct. 1, 2017: Stephen Paddock, 64, used a stockpile of guns including an AR-15 to kill 58 people and injure hundreds at a music festival in Las Vegas before he killed himself. Nov. 5, 2017: Devin Kelley, 26, used an AR-15 style Ruger rifle to kill 26 people at a church in Sutherland Springs, Texas, before he was killed. Feb. 14, 2018: Police say Nikolas Cruz, 19, used an AR-15-style rifle to kill at least 17 people at Marjory Stoneman Douglas High School in Parkland, Fla."