The Gunman who murdered 12 and injured 15 was thrown out of Navy two years ago because on gun charge

Gunman: According to NBC Washington, this man Aaron Alexis, 34, from Fort Worth, Texas is the Navy Yard shooter. A background check has revealed that this is the police mugshot for Alexis who was arrested but not charged for firing a gun in his apartment in 2010

Revealed: Washington Gunman, 34, who murdered 12 and injured 15 was thrown out of Navy two years ago because on gun charge

Emergency responders arrive at the scene of a shooting at the Washington Navy Yard in Washington, where several people were killed and others injured when at least one gunman opened fire at the U.S. Navy Yard

Aaron Alexis (right), the heavily armed gunman who calmly opened fire and killed 12 people this morning at Washington Naval Yard before being shot and killed was revealed to have a prior arrest for letting off a gun when he lived in Fort Worth, Texas, in 2010. 

The 34-year-old, who worked as a civilian contractor at the military base in the nation's capital, entered the complex's cafeteria just before 8.30am brandishing an AR-15 semi-automatic rifle, shotgun and handgun and began shooting. After SWAT teams swarmed the headquarters of the Naval Sea Systems Command the FBI said that Alexis was shot dead by officers.