Aaron Alexis had a valid secret-level government clearance when he walked through security and into Building 197 at the Washington Navy Yard last month.

He also carried a secret — a Remington 870 shotgun hidden in a bag.

Alexis, a Navy contractor, used the gun to kill a dozen people in the building, before police shot him dead.

Now, Congress is examining the background investigation that allowed Alexis to gain the security clearance.

A preliminary review indicates that the background check “was commensurate with current investigative standards for secret clearances,” Brian A. Prioletti, an assistant director in the Office of the Director of National Intelligence, said in testimony submitted for Thursday’s Senate Homeland Security and Governmental Affairs Committee hearing.

But are those standards good enough?

When Alexis was checked out in 2007, the standards prescribed a limited investigation, according to Elaine Kaplan, acting director of the Office of Personnel Management. “Those standards were records-based,” her statement said, “unlike the investigations for higher levels of clearance, and did not require that the investigator interview references.”

Holders of “top secret” clearances are reinvestigated every five years; it’s 10 years for those with “secret” clearances, and 15 years for employees and contractors in the “confidential” category. Alexis had four more years before he would have been checked out again.

Belatedly, that has proved not to be good enough in his case.

“One critical element for a robust security clearance process” is assessing “an individual’s continuing eligibility on a more frequent basis,” Prioletti said. “The time interval between periodic reinvestigations leaves the U.S. government potentially uninformed as to behavior that poses a security or counterintelligence risk.”

His statement to the committee, which is led by Chairman Thomas R. Carper (D-Del.) and ranking Republican Tom Coburn (Okla.), says that “Continuous Evaluation” (CE) is a tool that “includes automated records checks of commercial databases, government databases and other information lawfully available. Manual checks are inefficient and resource intensive. The CE initiative currently under development will enable us to more reliably determine an individual’s eligibility to hold a security clearance or sensitive position on an ongoing basis.”

The Navy Yard wasn’t the main focus of a House hearing Wednesday, but the tragedy was lurking in the background.

The Federal Protective Service (FPS) does not provide security for the Navy Yard, but a Government Accountability Office report released at a Homeland Security subcommittee hearing was critical of its operations. Some of the 13,500 contract security guards usedd by the FPS are not adequately trained, the GAO report said, particularly in incidents involving active shooters such as Alexis and the screening of people entering federal buildings.

“For example, according to officials at five guard companies, their contract guards have not received training on how to respond during incidents involving an active-shooter,” according to the report released at the oversight and management efficiency subcommittee hearing. “Without ensuring that all guards receive this training, FPS has limited assurance that its guards are prepared for such a threat.”

Three years after an earlier report on the lack of guard screener training, “guards continue to be deployed to federal facilities who have never received this training,” said Mark L. Goldstein, GAO’s physical infrastructure director.

One company told GAO that about 38 percent of its guards “have never received their initial X-ray and magnetometer training from FPS.”

“Consequently, some guards deployed to federal facilities,” Goldstein said, “may be using X-ray and magnetometer equipment that they are not qualified to use — thus raising questions about the ability of some guards to execute a primary responsibility to properly screen access control points at federal facilities.”

In a joint statement, Caitlin Durkovich, a Homeland Security assistant secretary, and FPS Director Leonard Eric Patterson told the subcommittee that FPS is working to improve training of contract security officers. Their statement did not directly answer all points in the GAO report, but it did provide generalities, such as “FPS is committed to ensuring high performance of its contracted PSO workforce.”

David L. Wright, president of the American Federation of Government Employees Local 918, which represents FPS employee law enforcement officers, was critical of both the GAO report and the protective service.

“Contrary to the broad brush of the GAO report, there are FPS regions in which all guards receive FPS training, untrained guards are never used at a screening post, guard firearms qualification is fully monitored and guards are trained on active shooter procedures at the facility they protect,” he said by e-mail.

Front-line FPS inspectors “spend weekends to ensure that contract guards are trained,” he said.

But, he added: “I make no excuse for supervisors and senior managers who have failed to ensure proper training in other regions. FPS contract guard issues should have been fixed. The FPS managers who have failed should be held accountable.”

Twitter: @JoeDavidsonWP

Previous columns by Joe Davidson are available at wapo.st/JoeDavidson.