Unauthorized immigrants who previously have been removed from the United States are more than 2.5 times more likely to be rearrested after leaving jail, and are likely to be rearrested much more frequently than those who have never been removed, according to a new RAND Corporation study.

The findings generally support strategies adopted by federal immigration authorities and some law enforcement agencies to focus their immigration enforcement efforts on immigrants who previously have been removed, who are viewed as posing a bigger criminal threat.

Researchers studied long-term recidivism rates among two groups of removable immigrants who had been released from the Los Angeles County jail: men who previously had been removed from the United States and men who had never been removed from the nation.

Published online in the journal Criminal Justice Policy Review, the study followed 517 foreign born men for nine years, and found that 91 percent of those who had a prior record of removal from the U.S. were rearrested during the study period compared to 64 percent of those with no history of removal. They also were arrested sooner following their jail release, and more frequently -- 4.5 times compared to 2.9 times -- than those who had never been removed from the U.S.

"If you are trying to target individuals who repeatedly cycle through the criminal justice system, this looks like a good risk marker," said lead author Laura Hickman, a professor of criminology and criminal justice at Portland State University and a researcher at RAND, a nonprofit research organization. "At least in our study, previous removal does seem to indicate something about increased likelihood for continuing criminal justice involvement."

An earlier study by Hickman and her colleagues showed that previous removal was a high risk factor for recidivism in the short term, with men who had a history of removal about twice as likely to be rearrested within a year of their jail release.

But short-term differences in recidivism don't necessarily predict long-term differences. To test whether previous removal continues to be a risk factor over the long term, researchers extended the study for an additional eight years. All men tracked in the study were released from the L.A. County jail between Aug. 4, 2002, and Sept. 2, 2002.

Removable immigrants are individuals who entered the country without authorization or the authorization they had has been revoked or expired, such as overstaying their visas. Federal immigration records were used to determine the men's immigration status to identify those removed prior to the 2002 Los Angeles County Jail stay. The researchers controlled for factors such as prior criminal history, age and current criminal charges.

In discussion of the comparison group findings (those without a record of prior removal), Hickman notes, "While 64 percent rearrested may seem very high, it's important to remember that this is a nine-year follow-up study. Other research on the entire Los Angeles County jail population found that 50 percent of released inmates were rearrested after just one year." Given the lack of other long term follow-up studies with similar populations, Hickman said "this prior research gives us a basis to suggest that 64 percent over nine years may not be too different from the population overall." Without additional study, however, "we just don't know."

After the data were collected in 2002, the U.S. Department of Homeland Security poured resources into border security and began a program known as Secure Communities, which screened all arrestees at local jails for immigration status and potential removal from the United States.

In its November executive action on immigration, the Obama administration announced an end to the Secure Communities program, which was criticized by groups opposed to local law enforcement participating in immigration enforcement. The Security Communities effort will be replaced by the Priority Enforcement Program, which will target interior immigration efforts more narrowly on those posing a distinct public safety risk.

"Since there are very few studies of unauthorized immigrants in local criminal justice populations, our results may be helpful information for the new Priority Enforcement Program," Hickman said. "In our data, it's clear that prior removal represents a solid predicator of repeat arrest over pretty long follow-up period, even taking into account criminal history."

Hickman notes, however, that more study is needed to confirm these results in other settings.