Ian David Long, a former Marine gunner, legally purchased a Glock 21 that he used to kill 12 others at a bar Wednesday night in Thousand Oaks, according to the Ventura County Sheriff’s Office.

It was the only weapon used in the attack, according to Ventura County Sheriff Geoff Dean, who said the gun also had an extended magazine. ... Gun used was a Glock 21 .45-caliber handgun.

Extended magazines available for sale on the Long's model of Glock can hold 21, 30 or more rounds. Read more: At least 13 dead, including the gunman, at college bar mass shooting in LA suburb of ...