This article is cross-posted from Just Security.

A key strategy in the Trump administration’s advocacy for its signature Muslim ban and “extreme vetting” policy initiatives has been to portray immigrants as especially prone to violence and terrorism, and as serious national security threats. The administration has advanced this narrative by misleadingly presenting government data to paint a picture that is at odds with copious empirical evidence.

Last year, President Donald Trump, addressing a joint session of Congress, said, “the vast majority of individuals convicted of terrorism and terrorism-related offenses since 9/11 came here from outside of our country.” His claim seems to have derived from data held in the National Security Division of the Department of Justice (DOJ) and relied on a methodology used by then-Senator Jeff Sessions, who, in 2016, represented that the data showed foreign-born persons were mainly responsible for terrorism in the United States. A version of the claim was echoed in a January 2018 report put out by the DOJ and the Department of Homeland Security (DHS). After that report was issued, the president trumpeted on Twitter that a “new report from DOJ & DHS shows that nearly 3 in 4 individuals convicted of terrorism-related charges are foreign-born.”

This is sophistry. The president did not specify that the data underlying his claims only counted international terrorism and failed to include domestic terrorism, which by any objective measure is at least as much of a threat. According to the FBI, international terrorism involves activity related to foreign terrorist groups versus domestic terrorism, which is linked to U.S.-based organizations, and is more often perpetrated by those born in the U.S. Indeed, a DOJ response to FOIA requests shows it’s doubtful that the White House was provided with data on domestic terrorism, which would have been needed for the president to present a complete picture of the threat posed by terrorism overall.

One part of the Justice Department has the relevant data. The Executive Office of U.S. Attorneys (EOUSA) maintains a database that acts as a repository for information on federal prosecutions around the country. This database — the Legal Information Office Network System (LIONS) — indicates that, since 2001, prosecutors have labeled at least 1,366 publicly filed actions as “domestic terrorism.” This number is likely an undercount because many domestic terrorism cases are categorized as hate crimes or are dealt with under state law. If items from the pool labeled “domestic” terrorism in LIONS were added to what the administration has presented as terrorism more broadly (but only includes “international” terrorism), its claims would likely be untenable on their own terms. And that’s ignoring all the ways in which DOJ has overstated the number of international prosecutions and whether it’s appropriate to divide Americans by their degree of separation from foreign ancestry.

But we still need more information to better understand how the federal government prosecutes terrorism. That’s why the Brennan Center — along with University of North Carolina at Chapel Hill Professor Charles Kurzman, who regularly publishes terrorism data — filed a Freedom of Information Act lawsuit this week to compel the disclosure of the judicial docket numbers related to public federal terrorism prosecutions. Such a disclosure would allow us to examine court records and learn more about the cases identified as “domestic terrorism” in the DOJ’s LIONS database. These docket numbers are already in the public domain, but EOUSA refuses to release them in aggregated form, making it near impossible to undertake a comprehensive assessment of relevant cases.

Information gleaned from reviewing these court records would help provide critical context for the Trump administration’s proffered terrorism data, which carry the imprimatur of the government. But it would also help us understand exactly what conduct federal prosecutors identify as domestic terrorism and who is targeted in these cases. Many people equate domestic terrorism with white supremacist and neo-Nazi violence. In fact, the FBI, in the decade following September 11, 2001, called eco-terrorism — by environmental activists — the number-one domestic terror threat, of greater magnitude than right-wing extremism and equal to al Qaeda. And the Bureau recently began to target “Black Identity Extremists” in an initiative redolent of its previous operations against black civil rights leaders in the 1960s.

For all these reasons, we need more data on how the federal government views terrorism. The implications are broad: Better understanding it is critical to informed discourse on issues ranging from immigration to foreign policy to the appropriate allocation of counterterrorism resources.

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