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In 2008, all members of Utah's congressional delegation signed a letter to the U.S. Department of Homeland Security suggesting what many in the state believe: Undocumented immigrants are responsible for much of Utah's crime.
"Numerous illegal aliens are committing crimes in Utah communities with virtual impunity," the letter read.
But research from Brigham Young University attempts to quantify Utah's crime rate for undocumented immigrants. The findings so far indicate undocumented immigrants commit no more violent and property crime than those born and raised in the United States. By some measures, they commit less.
Charlie Morgan, an associate professor of sociology at BYU, examined data collected from Utah jails and found inmates with detainers placed on them by U.S. Immigration and Customs Enforcement represented only 2 to 5 percent of jail inmates statewide. A "detainer" means ICE does not want the inmate released from the jail because that person might be deported.
The 5 percent figure reflects the fact that many of those inmates with detainers are only in jail because they have already been determined to be undocumented and await deportation not because they are accused of any other crimes. ICE contracts with jails in Weber and Utah counties to hold those inmates.
Utah has an estimated 100,000 undocumented immigrants, a number that represents 4 percent of Utah's population.
In 2009 the U.S. Census Bureau estimated 7.9 percent of Utahns were foreign born, but that figure does not distinguish immigration status. New census numbers will be released this year.
Morgan found similar rates in Utah's prisons. Over a nine-year span, 4.5 percent of prison inmates were undocumented immigrants, according to Morgan's research.
The figures at the prisons were higher for a pair of violent-crime categories. Data showed undocumented immigrants represented 12 percent of the 655 inmates in prisons for a murder conviction.
For convictions requiring entry on the sex offender registry, undocumented immigrants were 9 percent of the 2,053 such Utah prison inmates, Morgan found.
But Morgan cautions that does not necessarily mean those are the rates at which undocumented immigrants commit those crimes. Morgan said it's possible undocumented immigrants are not receiving parole as quickly as U.S.-born inmates and could be accumulating in prison.
Some of the jail data came from a 2009 report by the Sutherland Institute. State Rep. Chris Herrod, R-Provo, has criticized how the institute compiled its data. Specifically, Herrod pointed out that some county jails in Utah also hold state prison inmates, and the Sutherland Institute made no distinction in those instances.
Herrod also claimed the institute took only a "snapshot" of the jail populations over a few days rather than compiling long-term data.
The Utah Commission on Criminal and Juvenile Justice is investigating how many immigrants in Utah commit crimes. Commission research consultant Ben Peterson said it's been difficult to determine who is in the country illegally and who is not.
"The problem is that data is not reliable," Peterson said. "It either relies on the offender self reporting they're here illegally or it can be a deportation case, and if they're here on a green card, they forfeit their green card if they're convicted of a crime."
Peterson plans to contact statistical analysts in other states to see how they have collected data.
In an e-mail to The Salt Lake Tribune, Morgan said he found the institute's data to be "fairly accurate." But, in a draft of a paper Morgan intends to publish, he noted some factors may skew the figures in either direction.
• Jails and prisons may not accurately determine who is an undocumented immigrant.
• Some inmates awaiting deportation may not have lived in Utah. ICE does not have holding facilities in Idaho and Montana and brings undocumented immigrants to Utah jails.
This is not Morgan's first attempt at quantifying immigrant crime. As a doctoral candidate at the University of California-Irvine, he collaborated on research with sociology professor Rubén Rumbaut. In 2009, Rumbaut published research stating immigrants in Southern California and nationally are associated with less crime and less incarceration.
In an e-mail to The Tribune, Rumbaut said immigrants nationally commit proportionately fewer violent and property crimes than people born in the United States.
"I am NOT aware of a single reputable study that shows that immigrants commit more crimes than the general [native] population," Rumbaut said.
Do undocumented immigrants commit more crimes?
The claim • Undocumented immigrants are responsible for much of the crime committed in the state.
The reality • Undocumented immigrants commit no more crimes than legal residents, and by some measures, they commit fewer.
P Do undocumented immigrants dodge taxes and send a significant portion of their pay abroad?
Read more from immigration series
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