One in five Fairfax County residents is an illegal immigrant or lives with one, expert testifies

Published May 14, 2026 2:17pm ET | Updated May 14, 2026 2:17pm ET



Illegal immigrants reportedly comprise as much as one-fifth of the population of Fairfax County, a Northern Virginia sanctuary jurisdiction in the national spotlight for several murder cases involving illegal immigrant suspects.

An expert witness called to testify before Congress on the “Dangerous Consequences of Sanctuary Policies” told the House Judiciary immigration enforcement subcommittee Thursday that 1 in 5 Fairfax County residents are either in the country illegally or living with someone who is there illegally.

“About 1 in 5 Fairfax residents is someone who could be deported or who lives with them,” David Bier, the director of immigration studies at the Cato Institute, testified at Thursday’s hearing.

Fairfax County is the most populous county in Virginia, home to more than 1.1 million people, according to 2024 Census Bureau estimates. By the Cato Institute’s calculations, that means as many as 220,000 illegal immigrants, or 20% of the county’s total population, could reside in Fairfax County.

Data from the Migration Policy Institute place the number of illegal immigrants, including visa overstayers, across all of Virginia at approximately 361,000, as of 2023.

Opponents of lax immigration policies say Fairfax County’s sanctuary practices, such as refusing to honor federal detention requests, have attracted illegal immigrants to resettle there. Indeed, there has been a heavy concentration of criminally charged illegal immigrants in Fairfax County in recent years.

In fact, Fairfax County had the country’s third-highest release rate of illegal immigrants freed from pretrial detention, trailing only Santa Clara County’s main pretrial holding facility in California and Cook County Jail in Illinois.

In 2025, the Center for Immigration Studies ranked the Virginia suburb at No. 3 nationally by release volume out of sanctuary strongholds in the United States that routinely disregard detention requests from Immigration and Customs Enforcement.

HOW FAIRFAX COUNTY’S SANCTUARY POLICIES LED TO AN ILLEGAL IMMIGRANT MURDERING AN INNOCENT WOMAN

From October 2022 to February 2025, the Fairfax County Adult Detention Center released more than a thousand deportable illegal immigrants onto the streets in direct defiance of over 1,150 immigration detainers lodged with local officials, according to ICE records obtained by the CIS.

In terms of noncompliance, the CIS reported that Fairfax County, over that period, outpaced many other uncooperative facilities of much larger U.S. cities, including San Francisco County Jail at No. 9 with 462 declined detainers, Minnesota‘s Hennepin County Jail at No. 11 with 363, and New York City’s Rikers Island at No. 16 with 237.