In 2006, Kyle Aaron Huff used a Bushmaster when he opened fire at a post-rave party in Seattle, killing six before committing suicide. In 2007, Tyler Peterson used an AR-15 to kill six people at a homecoming party in Crandon, Wis. In 2012, a gunman opened fire at a movie theater in Aurora, Colo., killing 12 people and injuring 58 others. Police say James Holmes used a Smith & Wesson version of the AR-15 that was equipped with a 100-round drum magazine. And in December, Adam Lanza used a Bushmaster XM-15 in his massacre at Sandy Hook Elementary School, killing 20 children and six adults.