Authorities from the Bureau of Alcohol, Tobacco, Firearms and Explosives prepare to search a home in Hyattsville in 2011. The agency has struggled with antiquated systems, a lack of resources and, for the past six years, no permanent director. (Marvin Joseph/The Washington Post)

Amid an intense debate over gun control in the wake of the mass shooting in Connecticut, the federal agency at the heart of firearms regulation in America is so beleaguered and under-resourced that it has not had a confirmed director in six years.

The Bureau of Alcohol, Tobacco, Firearms and Explosives, a division of the Justice Department, is supposed to regulate the nation’s gun industry. But many within ATF say it is the industry that dominates the agency.

The gun lobby, concerned about government regulation of firearms ownership, has taken steps to limit the resources available to ATF and to prevent the agency from having a strong leader, according to former and current ATF officials.

For decades, the National Rifle Association has lobbied successfully to block all attempts to computerize records of gun sales, arguing against any kind of national registry of firearms ownership. And despite the growth of the gun industry and the nation’s population, ATF has fewer agents today than it did nearly four decades ago: fewer than 2,500.

“If the administration and Congress are serious about addressing this problem, they need to fund the gun police, the agency charged with administering the firearms regulations,” said Michael Bouchard, a former ATF assistant director. “Unless they are going to do this completely, simply passing some form of gun legislation is only part of the solution.”

John Lott, the author of “More Guns, Less Crime,” argues “gun-free zones” such as schools and movie theaters are magnets for mass murderers who know their targets won’t be armed. (The Fold/The Washington Post)

The man currently at the helm of ATF is B. Todd Jones, an interim acting director who works part time at the agency, juggling his position there with his job as U.S. attorney in Minnesota.

“ATF has struggled to competently enforce the firearms laws already on the books,” said Rep. Darrell Issa (R-Calif.), who has spearheaded a congressional investigation into the agency’s botched gun investigation along the Mexican border. “Posing a challenge to an agency needing consistent leadership, the acting director is currently working part time and out of Minneapolis.”

An ATF spokesman declined to comment.

President Obama’s nominee to be ATF’s permanent director is Andrew Traver, who oversees the bureau’s Chicago office. But his nomination has been stalled in the Senate for two years because Traver raised the ire of the gun lobby with comments it has characterized as anti-firearm. The NRA, which immediately opposed his nomination, has said Traver is linked to gun-control advocates and anti-gun activities in Chicago.

No permanent ATF director has been on the job in the six years since Congress required that the position be confirmed by the Senate. That action allowed the gun lobby to have a say on Capitol Hill about the agency’s leadership, according to ATF officials.

Even Michael J. Sullivan, a former U.S. attorney in Boston nominated by President George W. Bush, could not get confirmed. He was blocked by three senators who accused him of being hostile to gun dealers. One of the senators was a member of the NRA’s board of directors.

Past and current Justice Department officials say the gun lobby has further hampered the work of ATF by moving to block the government’s attempts to put gun-ownership records into an easily accessible computer database. When guns are used in crimes, such as the massacre in Newtown, Conn., ATF employees must go through an antiquated, laborious process, mostly done by hand, to trace the firearms to the stores where they were bought.

The agency, which has a budget of about $1.1 billion, is charged with investigating gun trafficking and regulating firearms sales. However, it is able to inspect only a fraction of the nation’s 60,000 retail gun dealers each year, with as much as eight years between visits to stores.

Officials from the NRA, which has about 4 million members, have said in past interviews with The Washington Post that the group’s work is designed to protect the constitutional rights of gun owners and has not hampered law enforcement.

ATF hurt itself in recent years with the bungled gun operation, known as “Fast and Furious.” Phoenix agents allowed U.S. firearms to pass into the hands of suspected gun smugglers in an effort to track the weapons to the upper levels of Mexican drug cartels. The agency lost track of about 2,000 guns, and two of the weapons were found at the scene of the fatal shooting of a Border Patrol agent.

The flawed operation led to a congressional investigation by Republican lawmakers and a contempt vote against Attorney General Eric H. Holder Jr.

Fallout from Fast and Furious also led to a major shake-up at ATF. Former acting director Kenneth Melson was reassigned and eventually left the Justice Department. Several top ATF officials were transferred or forced to resign or retire. An agency review board has recommended firing three officials involved in the case.

Still, police officials praise ATF’s ballistics and investigative work. The agency sent more than 30 agents and other personnel to Newtown for the investigation of the shooting at Sandy Hook Elementary.

Julie Tate contributed to this report.