An analysis released Monday by the libertarian Cato Institute shows that unauthorized immigrants and legal immigrants in Texas commit proportionally fewer crimes than the native-born population.

The study found that unauthorized immigrants had a criminal conviction rate 56 percent below that of the native-born people, said Alex Nowrasteh, a Cato immigration analyst and the study's author.

“And that tells us this is not a population that commits a lot of crime,” Nowrasteh said. “If it is true of Texas, it has got to be true in much of the United States."

Legal immigrants — a category that includes immigrants who became U.S. citizens — have even lower rates of criminal convictions, at 85 percent below the native-born, the study found. “Legal immigrants are much more law-abiding than virtually any other group in our society,” Nowrasteh said.

At the Center for Immigration Studies, a conservative think tank that advocates for more immigration restrictions, executive director Mark Krikorian said, "A lot of data does suggest immigrants are less likely to be involved in crime."

But the quality of the data hasn’t been good in past studies, said Krikorian, who hadn’t seen Nowrasteh’s report yet. Regardless, Krikorian said, “Even a single crime by one immigrant is bad because they are not supposed to be here.”

The study uses data from the Texas Department of Public Safety. Unlike other states such as California and Illinois, Texas law enforcement cooperates closely with federal immigration agencies, bolstering the accuracy of the data because of the sharing of details such as fingerprints, Nowrasteh said.

The report’s release comes as an immigration crackdown has become a signature issue for the administration of President Donald Trump. Trump and his allies frequently use crimes committed by immigrants in the U.S. without legal status to broadly position immigrants as dangerous.

In the report, Nowrasteh notes the tough executive order issued by Trump in his first week in office and Attorney General Jeff Sessions’ attempts to withhold federal funds from local police departments that don’t cooperate with the Department of Homeland Security. “Underlying both actions is a belief that illegal immigrants are a significant source of crime,” Nowrasteh wrote.

Texas Rep. Matt Rinaldi, R-Irving, an attorney who is a staunch critic of crime by immigrants, said, "Regardless of the rate at which they commit crimes, those particular immigrants should never have been in the country in the first place."

Kate Steinle case

Homicides also received a detailed examination by Cato.

That's due to the spotlight on the San Francisco murder acquittal of Jose Ines Garcia Zarate, a Mexican unauthorized immigrant, in the shooting death of Kate Steinle, who died on a pier while walking with her father. During Garcia Zarate's 2017 trial, jurors had to decide whether Steinle was killed in a freak accident or through intentional violence.

The San Francisco case has been cited numerous times as an example of deadly crime committed by immigrants in the U.S. without lawful status, and it galvanized support for tougher enforcement, Nowrasteh said.

“Kate Steinle motivated me to focus on homicides,” Nowrasteh said. “Murder is obviously the worst crime out there. It is what we rightly as a society focus on.”

In Texas, there were 951 homicide convictions in 2015. Unauthorized immigrants were convicted of 51 homicides and legal immigrants were convicted of 15.

The report found that the homicide conviction rate for unauthorized immigrants was 25 percent below that of native-born citizens. For legal immigrants, the rate was 87 percent below, the report found.

Nowrasteh zeroed in on the year 2015, although he had data through a public records request for 2011 through almost all of 2017, he said. The Cato analyst said conviction and arrest rates for the entire period were nearly identical to those of 2015.

In Austin, Tom Vinger, a spokesman for the Texas Department of Public Safety, said: "Crime is crime. From our perspective, law enforcement's role is to address all criminal activity."

As for the homicide conviction findings, Vinger said, “Every murder in Texas matters to law enforcement — and we’re confident victims’ families feel the same way.”

A spokesman for Lt. Gov. Dan Patrick, a frequent critic of illegal immigration, didn’t respond to a request for comment.

The study also found that the arrest rate for unauthorized immigrants was 40 percent below that of the native-born. The arrest rate for legal immigrants was 81 percent below that of native-born Americans. The arrest rate for all immigrants, regardless of legal status, was 65 percent below that of native-born U.S. citizens.

Unauthorized immigrants’ arrest rate for sexual assault was 3 percent higher than for native-born Americans. But conviction rates for unauthorized immigrants for sexual assault were 11.5 percent below the native-born.

When asked about the difference in arrests vs. convictions, Nowrasteh said: “A lot of sexual assaults are notoriously difficult to prove in court. It could be that they are even more difficult to prove against” unauthorized immigrants.