Citing FBI data, the report by Mayors Against Illegal Guns says the District has only submitted 80 mental-health records to the National Instant Criminal Background Check System, known as NICS, since the database was created in 1999. Maryland has submitted just 58 such records, and neither jurisdiction has submitted any substance-abuse records.
NICS has about 1.3 million mental-health records in total, but 23 states and the District have each submitted fewer than 100, the report found.
Federal law prohibits people who are seriously mentally ill or drug abusers from owning firearms. Without the state records in the NICS database, it's impossible for gun dealers to know whether a buyer has is barred from owning a weapon because of mental illness or substance abuse.
The gaps in the background check system have come under fire in the wake of the 2007 massacre at Virginia Tech and the January shooting in Arizona that left six dead and critically wounded Rep. Gabrielle Giffords. Virginia Tech gunman Seung Hui Cho was ordered to undergo psychiatric treatment in 2005, but his mental health records were never submitted to NICS. Jared Loughner, the alleged Tucson shooter, had a history of drug use but passed a background check.
"A variety of legal and policy barriers appear to hinder the submission of robust mental health information to the NICS," David Cuthbertson, an assistant FBI director, said in testimony to a Senate subcommittee last week.
An exception is Virginia, which has sent 161,334 -- the third most in the country.
After the Virginia Tech shootings, then-Gov. Tim Kaine ordered all records of mandated mental-health treatment to be submitted to the national database.
Maryland has a working group that's looking at the state's technology and information-sharing laws, said Greg Shipley, spokesman for the Maryland State Police.
"They've quickly seen that there's an issue with the infrastructure and legislation that both need to be addressed to bring us to where we should be," he said.
The District submits mental-health records for people committed to treatment in criminal court, said Phyllis Jones, chief of staff in the Department of Mental Health. Any other involuntary-commitment records are not submitted because the city's privacy laws prohibit the department from sharing the records, she said.
Submitting information is voluntary, but states are penalized by funding cuts if they don't send at least 50 percent of the requested records.