1. This is an AR-15-style semi-automatic assault weapon. Currently there are no federal restrictions on owning one.
2. Since 2012, the AR-15-style assault rifle has been involved in seven different large-scale shootings.
3. July 20, 2012: Twelve people were killed and 70 others were injured when James Holmes opened fire in a movie theater.
4. Dec. 11, 2012: Two people were killed and a third was seriously wounded in Clackamas County, Ore., when Jacob Roberts opened fire in a local shopping mall.
5. Dec. 14, 2012: Adam Lanza killed 26 children at Sandy Hook Elementary School using a AR-15-style Bushmaster semi-automatic rifle.
6. Feb. 19, 2013: Six people were shot and four were killed by Ali Syed in the cities of Tustin, Ladera Ranch, and Orange, Calif.
7. May 22, 2013: Jonathan Shank opened fire at a police officer in Longmont, Colo. The police officer was uninjured; Shank ended up in critical condition.
8. June 13, 2013: John Zawahri went on a shooting rampage in Santa Monica, killing five people and injuring four others.
9. Sept. 16, 2013: Suspected gunman Aaron Alexis allegedly shot and killed 12 people at the Washington Navy Yard reported as carrying a AR-15 military-style semi-automatic rifle.
10. Update - Sept. 17, 10:14 a.m., EDT: According to multiple sources, including CNN, the military are pulling back from early reports that Alexis was armed with an AR-15
The sources, who have detailed knowledge of the investigation, cautioned that initial information that an AR-15 was used in the shootings may have been incorrect. It is believed that Alexis had rented an AR-15, but returned it before Monday morning’s shootings. Authorities are still investigating precisely how many weapons Alexis had access to and when.
11. The New York Times, however, is still reporting an AR-15 was found on his person.
12. Update - Sept. 17, 2:06 p.m., EDT: The FBI has stated that they officially have no information about Alexis having an AR-15 in his posession during the attacks, contrary to earlier military reports.
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