President-elect Donald Trump may want to deport millions of undocumented criminals, but analysts say they exist mostly in his mind.

In an interview with CBS’ “60 Minutes” that aired Sunday, Trump said his administration would expel or imprison some 2 million or 3 million undocumented immigrants with criminal convictions. But Trump’s estimate greatly exaggerates the overall number of undocumented immigrants, experts say ― leaving them to wonder whether he’s still embracing the idea of mass deportation on which he campaigned, or whether he’s simply winging it at this point.

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“I don’t know where he’s getting these figures from,” attorney David Leopold told The Huffington Post. “It’s a figure that’s made up out of whole cloth. Trump is really showing that he doesn’t understand how immigration law was enforced under the Obama administration.”

Trump likely takes his estimate of 2 million undocumented criminals from a 2013 Department of Homeland Security report, according to a Washington Post article that criticized Trump’s “fuzzy math.” It’s not clear how he would have made the leap up to “even 3 million,” as he said on “60 Minutes.”

Even the 2 million figure cited by DHS, though, includes migrants who immigrated legally as well as ones who came to the U.S. illegally. And it makes no distinction between people convicted of serious crimes and people convicted of minor offenses.

In a widely cited report, the nonpartisan Migration Policy Institute estimates that the number of undocumented immigrants with criminal convictions is about 820,000. That figure encompasses a range of charges, including traffic offenses and convictions for illegally crossing the border. In other words, most of those 820,000 people aren’t the murderers or other violent criminals Trump says he wants to target.

The estimate for undocumented immigrants with felony convictions is even lower, at just around 300,000, according to the Migration Policy Institute. And even within this group, violent criminals account for only a percentage. Felonies can run the gamut from drug possession to homicide. Illegally re-entering the country after deportation is a felony.

U.S. Immigration and Customs Enforcement already prioritizes removing people who face serious criminal charges. And yet, people convicted of serious crimes make up only a small number of deportees.

Last year, ICE removed a total of 235,413 people from the United States. But a majority of them ― about 70 percent ― were apprehended near the U.S.-Mexico border while trying to enter the country.

The number of people removed from the interior of the country stood at 69,478. The vast majority of them were convicted of crimes, but it’s not clear in every case what the crimes actually were.

The highest level of criminality categorized by ICE, Priority 1, includes immigration offenses and drug offenses like marijuana possession, which some states might treat as a felony while others have legalized it entirely. Earlier this year, The Marshall Project obtained data for some 300,000 border and interior deportations between 2014 and 2016. They found that less than 20 percent of those deportations involved violent or potentially violent crimes.

ICE identifies people convicted of serious crimes in jails and prisons, and regularly carries out its own investigations to find and detain undocumented criminals. But Faye Hipsman, an analyst with the Migration Policy Institute, points out that those investigations are resource-intensive and lead to diminishing returns with each serious offender they deport.

“As more are removed, the numbers become smaller and it takes more resources to find them,” Hipsman said. “It’s difficult to imagine ICE finding and apprehending every single unauthorized immigrant with a criminal conviction in this country... It sounds unrealistic.”

Trump’s comments on “60 Minutes” also lacked a timetable, leading to further confusion over what he plans to do as president.

If those 2 million (or 3 million) deportations were to take place over one term, Trump would need to more than double the record-setting pace of the Obama administration’s first six years in office, when the U.S. expelled roughly 400,000 people per year. If, on the other hand, Trump is envisioning an eight-year timetable, he would only need to match Obama’s pace, not exceed it.

Trump’s efforts could be constrained by both the limited number of undocumented criminals and the need for more resources for Congress, according to Stephen Legomsky, a former head of U.S. Citizenship and Immigration Services.

At the same time, Legomsky told HuffPost, “I think, regrettably, it enflamed the passions of those who wrongly believe that undocumented immigrants are especially prone to crime.”

Trump’s comments also leave open the question of whether his administration would hit those high deportation figures by going after undocumented immigrants without criminal records. On the campaign trail, Trump pledged to scrap Obama’s executive actions that shield from deportation many undocumented immigrants who arrived as children. He also said he’d do away with a provision for undocumented parents of U.S. citizens or permanent residents.

“The reality is that there’s not going to be that many undocumented immigrants with serious criminal records to go after,” Legomsky said.

But, he added, nothing in U.S. law would stop Trump from prioritizing whatever group of undocumented immigrants he wants to remove.

Clarissa Martinez, deputy vice president of the civil rights group National Council of La Raza, said it’s hard to tell what Trump is thinking from the vague comments he offered to CBS. She feels heartened that support for immigration reform continued to poll well through a blustery campaign.

But she’s also concerned that Trump is reportedly considering many immigration hard-liners, like Kansas Secretary of State Kris Kobach and Sen. Jeff Sessions (R-Ala.), for top administration positions charged with carrying out deportation policy.

“In this cycle there’s a lot of mixed signals,” Martinez said. “But no matter what words Trump may be using, look at who he’s appointing to his transition team.”