John Russell Houser was deeply troubled long before he shot 11 people in a movie theater in Louisiana, but decades of mental problems didn't keep him from buying the handgun he used.

Despite public signs of mental illness - most importantly, a Georgia judge's order committing him to mental health treatment against his will as a danger to himself and others in 2008 - Houser was able to walk into an Alabama shop six years later and buy a .40-caliber handgun.

It was the same weapon Houser used to kill two people and wound nine others before killing himself at a Thursday showing of Trainwreck. Three people remained hospitalized on Saturday.

Court records strongly suggest Houser should have been reported to the state and federal databases used to keep people with serious mental illnesses from buying firearms, legal experts said.

"It sure does seem like something failed," said Judge Susan Tate, who presides over a probate court in Georgia and has studied issues relating to weapons and the mentally ill. "I have no idea how he was able to get a firearm."

Houser never should have been able to buy a gun, said Sheriff Heath Taylor in Russell County, Alabama, whose office denied him a concealed-weapons permit in 2006 based on arson and domestic violence allegations, even though the victims declined to pursue charges.

No evidence has surfaced of any criminal conviction that would have kept Houser from passing the background check required for many gun purchases. Federal law does generally prohibit the purchase or possession of a firearm by anyone who has ever been involuntarily committed for mental health treatment.

That's what happened to Houser in 2008 after his family accused him of threatening behavior, warning authorities that he had a history of bipolar disorder and was making ominous statements. His wife removed his guns and the family persuaded a judge to issue a protective order keeping him away once he left the hospital.

FBI's check system

At that point, court officials should have reported Houser's involuntary mental commitment to the Georgia database that feeds the FBI's background check system, which provides for a delay of up to three days when records suggest a buyer may be ineligible.

When Houser tried to buy his gun on Feb 26, 2014, the system only briefly delayed his purchase, according to a federal official who spoke on the condition of anonymity because of the ongoing investigation. The seller was advised the following day that the sale could proceed.

It was not clear on Saturday whether the judge who authorized authorities to detain Houser in 2008 filed a report with the Georgia Crime Information Center, which keeps about 5,000 records on people who cannot buy guns because they have been judged insane, involuntarily hospitalized or legally depend on someone else to manage their affairs. The judge did not return a phone message seeking comment.