In an interview with Fox News, Agriculture Commissioner Adam Putnam outlined his approach to illegal immigration if elected governor of Florida.

Florida has to act, Putnam said, because illegal immigration comes at a steep cost. Putnam touted his Secure Florida First Agenda, which includes establishing a community deportation system with U.S. Immigration and Customs Enforcement.

"In other words, Florida should have that relationship with ICE because Florida taxpayers are sick of paying tens of millions of dollars a year to feed and house in our prison system criminal illegal aliens who ought to be in the custody of the feds and oughta be deported," Putnam said June 7.

The economic impact of immigration is widely debated, so we wanted to take a look at Putnam’s statement. We found it’s uncertain how much money "illegal" immigrants in Florida prisons cost taxpayers. That’s because Florida doesn’t keep tabs on whether inmates are in the country legally or illegally.

Flaws in Putnam’s evidence

Putnam campaign spokeswoman Meredith Beatrice said that there are two ways to calculate the "tens of millions" dollar figure he is referring to.

The problem, though, is that his calculation for "illegal immigrants" includes inmates who are not U.S. citizens but are in the country legally.

Putnam’s team multiplied the total state Department of Corrections budget ($2.3 billion) by the percent of "criminal illegal aliens" in Florida’s prisons, which Putnam said was 4.8 percent. That 4.8 percent of Corrections budget is roughly $110 million.

In the second calculation, Putnam multiplied the average cost to incarcerate an inmate for a day ($55.80, according to the Florida Department Of Corrections) by the number of days in a year. Then he multiplied that total ($20,367) by the number of "criminal illegal immigrants" in Florida prisons, which he said was 4,754.

That works out to around $96.8 million.

But terminology matters. Putnam is referring to that 4,754 figure as all "illegal aliens," but in fact the state prison system labels them simply "aliens."

That might sound like a small difference, but it isn’t. The term "aliens" actually refers to all people who are not U.S. citizens, those who arrived both legally and illegally. The state of Florida only keeps a count of all aliens.

According to the Florida Department of Corrections, "the vast majority of alien inmates" are released to ICE for further immigration processing, including possible deportation.

It's possible undocumented immigrants make up a good share of the "alien" population, but Putnam still would have no way of knowing the exact numbers.

"If the state of Florida doesn’t track illegal immigrants in prison (they don’t) then that number is not knowable," said Cato analyst Alex Nowrasteh.

Another problem is that even if 4.8 percent of the prison population were released from the prison system, it does not mean it would have a direct 4.8 percent reduction on the total budget because of fixed costs, such as the cost to keep a prison running and administrative and security costs.

Bryce Peterson, a senior research associate at the Urban Institute, said that reducing a small number of people from the prison will only really reduce the cost of clothing, food and direct health care service to that individual. "If they were to release all 5 percent of those people that’s probably not going to be enough to start laying off people and closing prison," Peterson said. "It's unrealistic to think it's going to have a direct five percent impact on their total budget."

Our ruling

Putnam said Florida taxpayers "pay tens of millions of dollars a year to feed and house in our prison system criminal illegal aliens."

Putnam's estimates for how much undocumented immigrants in prisons cost Florida taxpayers have several major problems. For starters, the state only tracks inmates who are not U.S. citizens, without diving into whether they are in the country legally or illegally.

Even if we had the right numbers, experts told us that fixed costs for the prisons mean reducing the population yields uncertain cost savings. Eliminating a small percentage of inmates doesn’t mean the overall prison budget can be reduced by the same percentage.

We rate this claim Mostly False.