Just a couple of days after the Orlando massacre killed 49 people, including many Latinos in a gay nightclub, a House Homeland Security subcommittee pondered a national security issue that barely exists, at first glance at least.

The hearing on national security risks posed by visa overstays was planned well before Sunday’s shooting. While the timing was coincidental and Orlando was mentioned only to honor the dead and wounded, the reality of terrorism was ever present in the Cannon House Office Building hearing room.

“Time and time again, terrorists have exploited the visa system by legally entering America,” border and maritime security subcommittee Chairwoman Martha McSally (R-Ariz.) said in her opening statement. “The 9/11 Commission put it this way: ‘For terrorists, travel documents are as important as weapons.’”

Yet, the Department of Homeland Security (DHS) reports that overstays are rare, depending on how you view the data. The overstay rate for fiscal year 2015 was just 1.17 percent. “In other words,” four officials said in their joint testimony, quoting a department report, “98.83 percent had left the United States on time and abided by the terms of their admission.”

The problem, however, isn’t the percentage, it’s the number. That 1.17 percent equaled 527,127 individuals, more people than the population of Atlanta.

Because of that, the committee has pressed the department to develop a biometric system to document when visitors leave, so authorities will know who among them did not.

“Since 2003, we made substantial progress adding biometrics to the entry process and we now take fingerprints and photographs of most visitors entering on a visa,” McSally said. “But CBP [Customs and Border Protection] has made, in fits and starts, only marginal progress when it comes to biometric exit.”

More recently, DHS has experimented with various biometric exit tools and it has promised to launch a system at high-volume airports in 2018.  “Thankfully,” McSally said, “it appears that the Department has finally turned a corner.”

But it’s a hard corner to turn. Not only is technology needed, so is space, people and money.

“In pursuing a biometric exit system, DHS is cognizant of limitations posed by existing infrastructure,” the four officials said. “The United States did not build its land border, aviation, and immigration infrastructure with exit processing in mind.”

The four officials were Kelli Ann Burriesci, a deputy assistant secretary; Robert P. Burns, a deputy director; Craig C. Healy, an assistant director for national security investigations; and John Wagner, a deputy executive assistant commissioner with Customs and Border Protection.

They listed a number of problems such as the lack of designated airport areas for departing international passengers. Another issue was that travelers exit the country without being inspected by government immigration officials. Then there’s the “airports’ concerns that a biometric exit process not create an environment in which an airport cannot afford to support an international flight because that space is so highly restricted,” the officials said in their prepared testimony.

To inspect 95 percent of the relevant passengers at the top 30 airports, the officials estimated “would require 3,400 additional officers at an annual cost of $790 million, independent of any other costs, including considerable infrastructure costs, and cause significant delays.”

This would means Customs and Border Protection would have “to dramatically increase” its workforce and budget “and those costs would recur annually.”

Rep. Sheila Jackson Lee (D-Tex.) sought to place the overstay issue in another perspective.

“There may be many reasons why someone overstays their visa or remained in the United States beyond the time they stated,” she said, “what is important is that we do not assume a threat based on their nation of origin.”

She noted that Omar Mateen, identified by authorities as the Orlando shooter, was born in New York. The racist attack on Mother Emanuel United African Methodist Church in Charleston, S.C., last year, and the bombing of the Oklahoma City federal building in 1995, among others, also were the work of U.S.-born and -bred terrorists.

The “250 deaths at the hands of home grown violent extremists, as opposed to 50 by foreign terrorists” since September 11, 2001, Jackson Lee said, “is an important consideration when developing approaches to address the problem.”

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