“25 percent of federal inmates are noncitizens.”  

Crime by immigrants was brought front and center after a man who had been deported five times was charged with killing a young woman in San Francisco on July 1. The debate reached a fever pitch on the Fox News show Real Story with Gretchen Carlson.

Carlson paired former Clinton campaign adviser Simon Rozenberg with conservative talker and IJReview.com editor Larry O’Connor. In the span of two minutes, the two talked over each other about so-called sanctuary cities, border control and the Obama administration track record on deportations.

In the middle of this verbal melee — Carlson interjected with “Let me take control of this” — O’Connor said “25 percent of federal inmates are noncitizens.”

Rozenberg insisted O’Connor’s facts were wrong. O’Connor insisted otherwise. We thought we’d see what the data say.

O’Connor pointed us to the Federal Bureau of Prisons website and the numbers there fully support his statement.

As of the end of May 2015, 23.4 percent of the inmates (a total of 48,470) are not U.S. citizens. The largest share by far, 16 percent are Mexican, as this pie chart from the bureau shows.

That would seem to wrap things up neatly, but another division of the Justice Department has quite different numbers.

According to the most recent report from the Bureau of Justice Statistics, O’Connor overshot by about 100 percent.

The Justice Department statisticians reported a total of 25,800 noncitizen inmates as of the end of 2013. With about 216,000 prisoners across the board, the non-Americans make up 12 percent of the total population.

The time difference (2013 vs. 2015) doesn’t explain a difference of nearly 23,000 inmates. About the same gap was there in 2013, too.

So what’s going on?

According to Bureau of Prisons spokesman Ed Ross, when the folks at Justice Statistics (BJS) ask the prison folks to report their inmate numbers, they are told to exclude noncitizens housed in privately contracted facilities.

“Most of those who are in those contract facilities are deportable aliens,” Ross said. “They are convicted of a federal crime and are serving a federal sentence, and when they complete their sentence, we turn them over to ICE (Immigration and Customs Enforcement).”

And how many people are in those facilities? About 24,000.

So give or take, that’s where the difference is. And according to the Bureau of Justice Statistics, roughly 19,000 federal prisoners are behind bars for having violated U.S. immigration law.

The bottom line is that the percentages come out different because both agencies have about the same total head count, but when it comes to noncitizens, the Bureau of Prisons includes the people destined for deportation and the Bureau of Justice Statistics does not.

So who’s right? Well, it depends on what question you want to answer. If you want to know how many noncitizens are in prison for breaking a law that all citizens must obey — like not committing murder as in San Francisco — then you’d probably prefer the lower number from the Bureau of Justice Statistics.

If you want to know how many prisoners broke any kind of law, including sneaking across the border, then you’d find the Bureau of Prisons number more useful.

Our ruling

O’Connor said 25 percent of federal inmates are noncitizens. According to the Bureau of Prisons, that’s pretty much spot on. But it’s important to know that a hefty fraction of those inmates are only in prison for violating immigration laws and are in facilities more or less created to house them. If you take those people out of the equation, you’re looking at about 12 percent of federal inmates.

The claim is correct, but it overlooks a significant wrinkle. We rate it Mostly True.