WASHINGTON (CNN) -- States appear to be taking more action to keep guns out of the hands of people with mental health problems in the wake of the Virginia Tech shootings, new figures show.
Mental health problems would prohibit potential buyers from purchasing a gun.
Submissions of mentally ill patients' records to the FBI's National Instant Criminal Background Check System for gun buyers have more than doubled since the massacre in April, the Justice Department announced Thursday.
Currently, states are not required to send reports of mental health problems, which would prohibit buyers from purchasing a gun.
But after the shootings -- when a student with a history of mental health problems killed 32 people before taking his own life -- the number of submissions to the database grew from 174,863 during the first half of the year to 393,957 from July to November.
The number of states submitting the information also grew, from 23 before the Virginia Tech tragedy to 32 after it.
The majority of the new records came from California authorities, who submitted more than 200,000 entries, the Justice Department said. Ohio boosted the amount of entries from three in March of this year to 7,845 in November.
"Instant background checks are essential to keeping guns out of the wrong hands, while still protecting the privacy of our citizens," Attorney General Michael Mukasey said to the National Association of Attorneys General.
"But as we learned in the tragedy at Virginia Tech, the checks must be accurate and complete to be effective."
Virginia Tech shooter Seung-Hui Cho was judged a danger to himself and ordered to get outpatient mental health treatment in 2005, but there was no indication he followed up.
Virginia did not report his name to the FBI system because he hadn't been committed to a mental health facility.
Cho bought one of the guns he used in the massacre online from an out-of-state dealer, picking it up from a Blacksburg, Virginia, pawn shop after background checks were complete. He bought his other pistol from a Roanoke gun dealer a month before the shooting.
Officials say making sure information -- such as mental health records -- that would keep a person from buying a gun is available at a national level ensures that the individual doesn't go across state lines to try to make a purchase.
Background checks, however, aren't necessary for firearms purchases made at gun shows or from a private seller, which, according to estimates, account for about half of the guns sold in the United States each year. E-mail to a friend