WICHITA, Kan. -- As the first and only federal prosecutor in Kansas dedicated solely to handling criminal immigration cases, Barry Disney took a pragmatic approach to filing charges in an interior state that has become a mecca for immigrant labor drawn to its massive meatpacking plants and other food processing industries.

Limited resources were spent on the worst criminals who had been deported and then come back to the United States. Disney's first trial in federal court dealt with two illegal immigrants found speeding through Kansas with an assault rifle wedged in the back seat of a truck and loaded pistols hidden in the vehicle's speaker compartments. Agents had seized $16,000 in drug-tainted currency.

Disney's job as an assistant U.S. attorney in Kansas was created under a supplemental appropriation passed last year in the Southwest Border Security Bill, an initiative targeting criminal immigration cases and Mexican drug cartels. With the end of the federal fiscal year on Friday, the temporary funding for 81 immigration-dedicated federal prosecutors like him has also ended, Justice Department spokeswoman Jessica Smith said in Washington. Disney is one of 13 whose jobs were cut, while 68 others are being reassigned within the Justice Department.

"My frustration was that they added these positions in 2011 because they were needed; the need did not go away," Disney said.

Sixty-eight of the prosecutors will return to their old jobs and will still be able to work on Southwest Border Initiative cases, but not exclusively as they have for the past year, the Justice Department said. Justice officials have confirmed the reductions but have refused to elaborate on them.

"It is not that the U.S. attorney's office is going to ignore those crimes. It is just that they don't have someone whose sole responsibility is to do that," Disney said. "Fewer people are going to have to do more. They are dedicated to doing it. It's just going to be harder for them to do it."

Justice Department data analyzed by the Transactional Records Access Clearinghouse at Syracuse University found that criminal immigration cases filed in June accounted for 52 percent of new prosecutions in the nation's federal courts.

"The Obama Administration has been pushing and pushing on immigration, so that they choose to let these people go is kind of curious," said David Burnham, co-director of the Transactional Records Access Clearinghouse.

A TRAC analysis released earlier this year of criminal enforcement comparing the administrations of Presidents George W. Bush and Barack Obama found that immigration prosecutions in the districts along the southwest border increased 77 percent between fiscal 2007 and 2010 under Obama. Elsewhere in the nation, criminal immigration prosecutions during that same period were up 31 percent.

Burnham said that the loss of so few prosecutors is such a small percentage of the total that it will likely have little impact on immigration enforcement.

Nationwide, the Justice Department said it has 5,000-plus assistant U.S. attorneys. But that figure includes civil attorneys who handle cases like foreclosures and forfeitures. Criminal prosecutors also must handle all the other violations of federal laws, such as wire fraud, gun and drug cases, health care fraud, along with other white-collar crimes.

For example, the U.S. attorney's office in Kansas said it has 45 assistant U.S. attorney positions, but just 33 of them handle criminal cases spread across the three federal district courts in the state. Court records show that in the four months Disney held the federal prosecutor's job, he filed more than 50 criminal immigration-related cases. He left the U.S. attorney's office in in July to take a job as assistant county prosecutor in Riley County after finding out that the funding for his federal job was not being renewed.

Carl Tobias, a law professor at the University of Richmond who follows the federal justice system, said while the loss of 81 immigration-dedicated positions may not sound like much in the overall scheme of things, it could be a serious problem in border states and some interior states like Kansas, which are grappling with a large illegal immigration problem.

"In those specific districts experiencing heavy caseloads, especially on the border, I think in terms of judicial resources and DOJ resources it could be significant, and I expect it would put pressure on the remaining people in the office," Tobias said.

Disney said his expectation when he accepted the Justice Department position was that the so-called term positions for specialized immigration prosecutors would be renewed, just as they are renewed each year for other prosecutors who are dedicated solely to handling gun or drug cases. He noted the Justice Department spent $10,000 for a four-month background investigation on him before he was hired. But he acknowledged the Justice Department, which has been under a hiring freeze since January, had a right not to renew the immigration positions.

"The reason why Kansas was awarded this position was because there was a need for it and the need is still there, but the position is not," Disney said. "They will just have to make do."