94 Percent of Non-Citizen Federal Prisoners Are Illegal Aliens

An inmate at the federal prison in Terre Haute, Ind., works on the sign, in April 2001. JEFF HAYNES/AFP/Getty Images

WASHINGTON—Ninety-four percent of foreign-born federal prisoners are in the United States illegally, according to a new report by the departments of Homeland Security and Justice.

Illegal alien prisoners could make up as much as 19 percent of the total number of prisoners in the federal system. The estimated population of illegal aliens in the United States is 3 to 4 percent.