Congress requires Immigration and Customs Enforcement to report statistics showing how many people are held in its detention centers overnight. But researchers say the data includes anomalies that indicate the Department of Homeland Security is underreporting detentions, and Democratic lawmakers want to investigate.
Each year’s funding bill for DHS has a mandate for the department to disclose twice a month the average number of individuals held at its detention centers. According to the agency’s most recent report, which was published last week, those numbers abruptly dropped at 96 facilities by an amount that one researcher said literally does not add up.
“The numbers that ICE reported for some of these detention facilities were too low to be possible. An average at that point cannot drop that far, that quickly,” Adam Sawyer, a data researcher and former associate at Syracuse University’s Transactional Records Access Clearinghouse, told NOTUS.
Sawyer noted that the sudden drop points to errors somewhere in ICE’s data reporting — either the current report was underreporting detentions and had too few, or prior reports had overreported them and had too many. The latest report included data from Oct. 1 through July 7.
An ICE spokesperson called NOTUS after publication to attribute the miscount to “human error” made by a contractor. ICE said the data in its most recent report, including data up until July 7, was accurate.
The error caught the attention of Democrats on the Senate Committee on Homeland Security and Governmental Affairs, including the committee’s ranking member, Sen. Gary Peters.
“Our office is looking into this,” a committee aide told NOTUS via email. “Senator Peters believes that Congress and the public need transparent and accurate data about ICE’s operations — especially given the significant resources provided to ICE in reconciliation — to effectively conduct oversight.”
Democrats have criticized the Trump administration’s lack of transparency as it undergoes its full-throated, multiagency mass deportation agenda.
Still, Republicans gave the agency $75 billion in funding through 2029 to bolster its detention systems and removal operations in their recent reconciliation package. If they use ICE data, lawmakers don’t have a clear picture of what that detention system currently looks like: More than half of the facilities that ICE reported numbers for contain mathematically impossible statistics, Sawyer’s research found.
Speaking generally, Rep. Maxwell Frost said that ICE has been operating with “no transparency,” which is why he led a proposal for a bill last month that would force ICE to release more statistics about the people it’s holding in its facilities. Besides what Frost observed on his tour of “Alligator Alcatraz” last month, what little other information he has about its detainees is from documents leaked to local news outlets, he said.
“They’re moving so fast and doing shit so carelessly that their numbers aren’t right, and no one knows where people are at. U.S. citizens have been deported. Veterans are being detained,” Frost told NOTUS. “We’re not able to fully conduct our oversight because the administration is illegally impeding that — from letting us into buildings, from ICE publishing who’s in which facilities.”
When ICE reports its detention data, it calculates an “average daily population,” or ADP. It determines that figure by adding up the daily population in detention centers for the days in the reporting period and then dividing it by the number of days.
While an ADP can decrease — like if there are fewer detainees held at any one center from one day to the next — there is a limit to how much that average can fall in a short time because of the overall nightly stays that have already happened. The number of days always increases, even when ICE reports that the ADP went down.
But Sawyer found that the cumulative total of nightly stays dropped at dozens of ICE detention facilities, suggesting the possibility of data loss somewhere along the line.
Those facilities include some of the most high-profile ones, like the Central Louisiana ICE Processing Center in Jena, Louisiana, where Palestinian rights activist Mahmoud Khalil was held from March until his release in June.
Sawyer’s research indicates that the Jena facility lost more than 5,000 overall nightly stays, so-called cumulative detention nights, between ICE’s two most recent detention data reports.
ICE’s report from late June showed the facility had an ADP of about 1,177, which was calculated over 266 days. But two weeks later, it reported an ADP of about 1,100 over 280 days, meaning the cumulative stays, calculated by multiplying the ADP by the number of days elapsed, decreased from around 313,030 to about 308,021 — losing more than 5,000 overall, even though more days passed.
The Krome North Service Processing Center and the Broward Transitional Center in Florida are also highlighted in the research. The facilities are named in a recent report from Human Rights Watch alleging rampant abuses against detainees, including substandard medical care and overcrowding. Human Rights Watch researchers said the conditions would “meet the threshold for inhuman and degrading treatment.”
Krome lost just under 5,400 total overnight detentions that it previously reported. The Broward Transitional Center lost more than 6,500.
Sawyer said there’s no way for anyone to tell based on public information whether ICE’s reported sharp drops in detained populations resulted from calculation errors or deliberate manipulation. He pointed out that an easy way for the agency to rectify potential errors like this would be for it to publish both the facilities’ ADPs alongside the totals that ICE used to calculate them — which Congress could also add to its existing reporting mandate.
“Why not both?” Sawyer said. “There are numbers somewhere that have this, because you don’t get the average daily population without a total.”
Rep. Robert Garcia, a Democratic member of the House Committee on Homeland Security, told NOTUS that he already doesn’t trust information from the Trump administration.
“I actually just don’t trust numbers the administration is putting out, and I don’t think the American public should,” Garcia said. “We already know they are trying to limit the power of Congress to actually do any sort of oversight at the detention facilities. On data, they’re not giving us information.”
Immigration advocates have long raised concerns about the quantity and quality of the data that the federal government makes public about migrant detentions. According to a 2024 report from the Government Accountability Office, “ICE’s public reporting understates the total number of individuals detained” and that the agency fails to “fully explain the rationale and basis for its methodology” in its annual reports.
Concerns about data mismanagement are why some immigration enforcement watchdog organizations choose not to use ICE’s detention data.
“The Deportation Data Project seeks individual-level, anonymized data on noncitizens — different from the aggregated statistics in the detention spreadsheets — in part because we don’t want to take ICE’s word for it,” Graeme Blair, the organization’s deputy director, emailed NOTUS.
“We hope ICE will start proactively posting the individual-level data regularly — just like the immigration courts at the Justice Department and many other agencies do as they are required to by law,” he added.
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This NOTUS story was produced in partnership with Verite News and with NewsWell.
Editor’s Note: This story was updated with additional reporting.