The cost of holding undocumented immigrants in Texas county jails fell about 8 percent in 2013 from the previous year, according to data from the Texas Commission on Jail Standards.
The data tracks the number of days spent in jail by each person with a federal detainer from Immigration and Customs Enforcement. Using a formula to approximate the cost per night for each jail bed, the commission's data shows annual costs were about $77 million, or $6.4 million less than in 2012.
Brandon Wood, the commission's executive director, said the data could reflect a number of possible trends, including a reduced rate of illegal immigration, lighter sentences for undocumented immigrants or lower crime rates. "It means there were fewer inmates with the detainers in county jails," he said.
ICE, a federal law enforcement agency, issues detainers, or "immigration holds," as a primary means of apprehending noncitizens it suspects of being in the country illegally. The detainers serve as a request to local jails that they not release the suspects so that ICE can take them into custody.
Harris County Jail, the largest in the state and one of the largest in the nation, housed 14,500 undocumented immigrants in 2013, roughly 4 percent fewer than in 2012. Alan Bernstein, spokesman for the Harris County Sheriff's Office, said the decrease was not unexpected, because ICE issued noticeably fewer detainers last year.
He added that the true cost of housing undocumented immigrants is "elusive." In many small, rural jails, he said, undocumented immigrants stay beyond the time of their sentences, waiting for federal agents to take them into custody. But at the Harris County Jail, Bernstein said, inmates do not stay beyond their normal sentence, so no additional expenses are incurred.
At large, urban jails like Harris County's, "ICE picks up Monday through Friday," Bernstein said.
Virtually all county jails saw a modest decline in costs, but there were exceptions. Dallas County, which ranked third in the number of days undocumented inmates spent behind bars at its facility, spent nearly 17 percent more on housing those inmates in 2013, up to $8.4 million from $7.2 million.
Alex del Carmen, chairman of the department of criminology and criminal justice at the University of Texas at Arlington, said the data should be read "cautiously."
A bill authored by state Sen. Tommy Williams, R-The Woodlands, first mandated in 2011 that jails track the costs specifically associated with undocumented immigrants. Figures are not available for years prior to October 2011.
Del Carmen said an 8 percent drop might not signify anything more than a normal fluctuation in crime rates. On the other hand, he said, the data would also be consistent a lower rate of illegal immigration, a phenomenon he said was nearly impossible to measure.
"I am not suggesting that the influx of undocumented citizens has decreased necessarily, but there seems to be a general sense that it's harder now to survive in the U.S. as undocumented than it was 20 years ago," he said.
ICE policies may also have something to do with the decrease. Susan B. Long, a professor at Syracuse University who has tracked ICE detainers over time, said that while numbers varied from place to place, the number of detainers issued by ICE nationwide had fallen dramatically since 2011.
But, she added, "the national trend is a bigger drop than for Texas, and there's quite a bit of variation facility by facility."
While experts hailed the falling costs as a positive for the state, they cautioned against finding a political message within them.
"The conclusions you can draw are very, very limited," del Carmen said.
Disclosure: At the time of publication, the University of Texas at Arlington was a corporate sponsor of The Texas Tribune. (You can also review the full list of Tribune donors and sponsors below $1,000.)