More holes are being shot through an illegal immigration crime study quoted as fact by conservative lawmakers and media outlets.

The Cato Institute, a Libertarian think tank funded by the conservative Charles Koch Foundation, pointed out a flaw in fellow conservative John Lott's claim that illegal immigrants make up most of the inmates in Arizona's prison system.

Cato researcher Alex Nowrasteh looked closer at Lott's study and noticed he included all of the inmates who were non-citizen and deportable.

"That includes illegal immigrants, it includes a number of legal immigrants in the U.S. and includes other people like tourists, who are also in prison and deported," said Nowrasteh.

Since Arizona and most every state does not monitor whether inmates are undocumented Nowraseth looked at the one state that does track it, Texas.

"And found, that illegal immigrants are substantially less likely to be convicted of crimes in the state of Texas than are native born Americans," he csaid. "The results there are the exact opposite of the John Lott study."

Nowrasteh said that aligns with research showing people who take great risk to move to another country for stability are far more likely to stay out of trouble.