WASHINGTON — In the hours following the San Bernardino, California, shooting, a frustrated President Barack Obama called for Congress to pass a law that would prevent individuals on the “No Fly List” who are barred from boarding commercial flights from legally purchasing firearms.

Under current federal law, there is no basis to automatically prohibit a person from possessing firearms or explosives because the individual appears on the terrorist watchlist. However, a felony conviction or illegal immigration status are disqualifying factors.

Membership in a terrorist organization does not prohibit a person from possessing firearms or explosives under current federal law. However, for homeland security and other purposes, the FBI is notified when a firearm or explosives background check involves an individual on the terrorist watchlist.

CNN has learned from January 2013 to December 2014, FBI data show that individuals on the terrorist watchlist were involved in firearm-related background checks 485 times, of which 455 (about 94%) of the transactions were allowed to proceed and 30 were denied.

Of the 30 transactions involving individuals on the terrorist watchlist that were denied during calendar years 2013 and 2014, FBI data show that the reasons for denials included felony conviction, under indictment, adjudicated mental health, misdemeanor crime of domestic violence conviction, fugitive from justice, and controlled substance abuse.

Overall, since the FBI started checking against terrorist watchlist records in February 2004, data show that individuals on the terrorist watchlist were involved in firearm or explosives background checks 2,233 times, of which 2,043 (about 91%) of the transactions were allowed to proceed and 190 were denied.

The FBI does not know how often a firearm was actually transferred or if a firearm or explosives license or permit was granted, because gun dealers and explosives dealers are required to maintain but not report this information to the FBI.

All of this data were outlined in a letter from the Government Accountability Office to Democratic California Sen. Dianne Feinstein at the senator’s request.

Senate Democrats forced a vote Thursday on language which would give the U.S. Attorney General to deny the transfer of firearms or the issuance of firearms and explosives licenses to suspected terrorists if it is reasonably believed those individuals may use firearms or explosives in connection with an act of terrorism. The amendments were offered as part of the Republican budget bill intended to repeal portions of Obamacare and defund Planned Parenthood. The amendments failed to advance because it did not get the 60 votes needed.

On the House side GOP Rep. Peter King of New York has sponsored a bill that would make it illegal for people on the no-fly list to buy guns. But, so far, the bill has gone nowhere in Congress.

The two individuals police say are responsible for the bloodshed in California were not on any terror watchlists and did not have criminal records but law enforcement is exploring whether they had been radicalized. The male shooter, Syed Rizwan Farook, had been in contact with more than one terrorism subject who the FBI were already investigating, according to law enforcement officials.