On The Last Word with Lawrence O'Donnell on Wednesday, the host interviewed a former agent with the Bureau of Alcohol, Tobacco and Firearms, who discusses the ways in which he claims the agency is blocked from taking almost any action to regulate guns.

On Dec. 19, President Obama noted that Congress hasn't approved a director for the ATF in six years, "the agency that works most closely with state and local law enforcement to keep illegal guns out of the hands of criminals."

"I'd suggest that they make this a priority early in the year," he said.

A recent New York Times article detailed the myriad restrictions on the agency that prevent it from tracking gun purchases and gun ownership.

For instance, the ATF cannot build a federal registry for gun transactions and must make a series of phone calls to manufacturers, wholesalers and dealers, as well as wading through paperwork and handwritten index cards, when it needs to trace a gun and serial number. That's because Congress, siding with the National Rifle Association, said a database would threaten the Second Amendment.

William Vizzard, a special agent with the ATF for 27 years who is now a professor of criminal justice at the UC-Sacramento, countered that line of reasoning.

"They've been disabled largely by the Firearms Owners Protection Act of 1986, the McClure-Volkmer Act, from a number of things. The ability to control dealers who violate the law was greatly limited," Vizzard said adding that "Controlling unlicensed dealing is virtually impossible. And the original gun control act of '68 didn't really extend much authority to ATF, and the '86 statute cut that back substantially."

Even discarding additional regulations, he said, "The underlying law really does not provide the mechanism to regulate gun commerce."

MSNBC political analyst and former DNC communications director Karen Finney said most Americans would find it inconceivable that there is no such database.

"I can't buy Sudafed one day early because of the computer database system that tracks how much you buy and when you buy it," she said, but "there isn't a system that, where for example a police officer, let's say in Aurora, Colorado, would know that someone in their community was amassing large amounts of weapons and ammunition."

Not only is there no database, but background checks conducted on individuals buying guns are destroyed after 24 hours.

"There's never been an effective system of recording gun transactions," he explained.

He said the NRA has also lobbied for a law that allows people to "buy as many weapons as they want of any type, and walk out the door with them at that moment, without any check without any, other than a criminal records check." Theoretically, he said, that would mean someone could walk in and buy 50 semi-automatic rifles and "walk out the door with them" without any notifications to ATF or to any database.

He said that "a whole series of things" are needed for the ATF to operate better, including a database, better laws regarding unlicensed dealers and more controls on dealers.

He explained, for instance, that an audited dealer missing a thousand guns -- which he claims has happened -- could only be charged with a misdemeanor, although it is likely the dealer sold the missing guns illegally.