13 people died following a shooting rampage at the Naval Sea Systems Command headquarters in Washington, D.C. on Monday.
The reported gunman, Aaron Alexis, 34, went on a two-hour rampage, killing 12 before D.C. police officers eventually shot him dead, according to Reuters.
Authorities said that Alexis entered the base armed with only a shotgun, but then obtained access to a handgun after he started shooting and wounding co-workers.
3,000 employees were locked down in their offices during the two-hour period, during which police pursued the shooter. Alexis was reported to have been armed with an AR-15 assault rifle, a shotgun and a handgun. According to The L.A. Times, investigators believe Alexis began the assault with only the shotgun and that he took the AR-15 rifle and the handgun from people he shot.
Officials said that Alexis eventually made it to the fourth floor of the headquarters of the Naval Sea Systems Command building, where he started shooting down into an atrium that houses an employee cafeteria.
Officials say that there is no certainty about the motive behind the shooting, but there is no indication that the incident is connected to a terrorist plot.
