Fact Check: Trump's claims on undocumented immigrant crime rates. Here's what the numbers show.

President Donald Trump, speaking in New Orleans on Monday, listed tens of thousands of crimes he said were committed by undocumented immigrants, part of a pattern of statements he’s made linking immigrants to crime in his effort to gain support for his proposed border wall.

It echoed his prime-time address last Tuesday in which he used the same numbers.

Here’s the problem:

There is no national database that compares crimes committed by immigration status. In fact, only one state – Texas – does so. That means there’s no national database that breaks down crimes committed by native-born citizens or immigrants, or those in the country illegally, making it difficult to confirm or dispute the president’s numbers.

What available studies do show, however, is that overall, crime rates are lower among immigrant groups than they are among native-born Americans.

The broader context: crime rates among immigrants are lower

Walter Ewing, an editor and writer for the American Immigration Council, a group that advocates for immigrants, puts it this way: “You can find any demographic group that you like and it’s going to include murderers. You can look at redheads and blondes and it’s going to include murders. But that’s not the point, the point is what the crime rates are,” he said.

Comparing overall crime rates for different groups is the best way to determine if a particular group poses a significantly greater threat than others.

“And if the likelihood is low, particularly compared to natives, then it’s disingenuous to claim they’re going to be a threat,” Ewing added.

Alex Nowrasteh, a senior immigration policy analyst with the libertarian Cato Institute, points to Texas as an example, since it’s the state with the best data on crimes committed and counted by immigration status and was the subject of a recent report he wrote showing that criminal conviction and arrest rates for immigrants were "well below" those of native-born Americans.

Here’s the breakdown:

Undocumented immigrants make up just over 6 percent of the state's population, legal immigrants made up over 10 percent, and native-born Americans make up over 80 percent, according to the most recent American Community Survey data and the Center for Migration Studies.

Meanwhile, undocumented immigrants were convicted of 5.9 percent of all the homicides in Texas, legal immigrants were convicted of 3.8 percent of homicides, and native-born Americans were convicted of about 90 percent of all the homicides in Texas, according an analysis of 2015 Texas state data by Nowrasteh.

In other words, native-born Americans were the only group over-represented among those convicted of homicide in the state.

The president has also pointed to Texas, citing -- mostly accurately -- numbers from the Department of Safety in a tweet over the weekend: “In the Great State of Texas, between 2011 & 2018, there were a total of 292,000 crimes by illegal aliens, 539 murders, 32,000 assaults, 3,426 sexual assaults and 3,000 weapons charges. Democrats come back!”

But the context is important here, too. Trump doesn’t include a comparison to the general population’s crime rates, and the numbers Trump cited are arrests, meaning all did not result in convictions. Of those charges over eight years, 238 undocumented immigrants were convicted of homicide, 13,559 for assault, 1,689 for sexual assault and 1,280 for weapons.

And that all, in the end, frames a bigger picture: undocumented immigrants are about half as likely to be incarcerated as native-born Americans and legal immigrants are about 80 percent less likely than native-born Americans, according to Nowrasteh’s research for the Cato Institute.

But where are the president’s nationwide numbers on crime committed by those in the country illegally coming from?

Though the White House did not specify, the president is likely gleaning numbers from data released by Immigration and Customs Enforcement (ICE) that summarizes arrests of immigrants who are released into their custody and then removed from the country. But the information Trump appears to be using does not make clear what year the arrests were made, when the crimes were actually committed, and combines charges with convictions.

According to the data, serious drug and DUI offenses represent the largest group of convictions, followed by immigration and traffic offenses.

The 266,000 arrests of undocumented immigrants with criminal records over the past two years that Trump mentioned is a number that mainly includes immigrants who were convicted of crimes in the past, and perhaps served jail time before they were released into ICE custody.

As Nowrasteh puts it, “this is just when ICE gets them. It isn’t when convictions happened.”

According to the ICE data, over the past two years, there were nearly 4,000 arrests made for people charged and convicted of homicide among immigrants released into ICE custody for deportation -- but the homicides could’ve been committed over any number of years.

For comparison, just in 2017, a total of 16,446 people were murdered in the U.S., according to the FBI.

The same unclear time frame applies to the president’s number on assaults, which likely stems from the nearly 50,000 people released into ICE custody in 2017 and 2018, who had been either charged or convicted for such crimes -- but who could have committed their crimes years ago.

As for the president’s statement on sex crimes, those same ICE reports do not show 30,000. Even when combining the number from the ICE reports on sexual assaults with the separate category of sex offenses, that total comes to around 22,000.