How was Aaron Alexis, with psychiatric problems and two shooting incidents, allowed to keep and bear arms?

Current Federal laws that require a background check prior to the purchase of weapons are supposed to look for criminal activity, especially gun-related and violent crimes, as well as psychiatric problems. Yet, every single mass-murdering gunman since 1963 has had known psychiatric problems and was on SSRI drugs. We do not yet know if Alexis was on SSRIs but we do know he had two previous incidents where he illegally discharged a firearm. He was discharged from the Navy for disciplinary problems. He has known psychiatric problems, including "anger management," and PTSD.

It is outrageous that some are already calling for more gun control laws when the laws we have now are not being used. It is more outrageous that adverse psychiatric information is seldom reported by doctors and hospitals.

Finally -- He purchases the weapons, including the AR-15 within the last week.