PHOENIX (AP) — When U.S. Attorney General Jeff Sessions delivered his get-tough-on-immigration speech in the border city of Nogales early this year, he promised a “new era” in immigration enforcement.

Six months later, some of those promises are taking shape in federal court, but through the expansion of a nearly decade-old program known as Operation Streamline, in which immigrants accused of coming into the U.S. illegally complete a usually months-long prosecution process in one day. Critics say the program violates due process and does nothing to deter repeat offenses.

In Arizona, federal authorities are now prosecuting first-time border crossers – heavily increasing the program’s caseload – after years of prosecuting only repeat offenders. The move is a small part of the overall increase in immigrant prosecutions that Sessions has called for.

Just how effective Operation Streamline is at reducing repeat border crossings is unclear.

A report by the U.S. Government Accountability Office this year found that the way the Border Patrol calculates recidivism rates in programs such as Operation Streamline results in lower figures by only considering whether a defendant re-entered illegally within a year.

The Border Patrol finds only 14 percent of migrants who go through programs designed to deter border crossings reoffend. The Government Accountability Office puts that figure at 29 percent based on its own methodology, which the Border Patrol has declined to adopt.

Customs and Border Protection spokeswoman Jennifer Gabris said the recidivism rate for defendants who go through Operation Streamline was about 8 percent in the 2016 fiscal year.

The Border Patrol’s Tucson Sector, which comprises most of Arizona, is one of four in the nation that still use the program.

In these court hearings, dozens of immigrants who were just caught crossing the border are assigned an attorney, go before a judge, plead guilty and are sentenced all within a day.

In recent years, there were few defendants in Tucson because there weren’t as many migrants caught crossing and first-time offenders weren’t being prosecuted.

As of this spring, when the agency decided to resume prosecutions of first-timers, hearings are held four days a week and with close to the maximum number of defendants per hearing, which is 70.

In August, U.S. Marshals led small groups of mostly men into a federal courtroom. The men stood in front of their court-appointed attorneys and listened to a judge give instructions, tell them their rights and ask questions through a translator.

Still in the clothes they were wearing when they got caught, some appeared confused when asked questions.

A judge read them their rights and asked a series of questions, including if they were pleading guilty. All of them did.

Federal prosecutors in California, unlike those in Arizona and Texas, have rejected Streamline, considering it an ineffective drain on resources. Karen Hewitt, the top federal prosecutor in San Diego from 2007 to 2010, is quoted in a 2010 University of California, Berkeley Law School paper, saying that pursuit of more serious offenders was “consistent with what the public (in California) would like to see.”

Border Patrol Chief Rodolfo Karisch, who took over as head of the Tucson Sector in August, said programs like Operation Streamline are necessary to show migrants who cross the border illegally that there are consequences to their actions. He said the program in Tucson has been successful.

“At the end of the day, if you simply arrest someone and nothing ever happens to them, then they just continue to come back,” Karisch said.

But many migrants do come back.

Take Ernesto Dorame-Gonzalez, a Mexican man who was has been arrested for crossing the border illegally multiple times since at least July 2013, according to court records.

He was caught again in October 2014 and prosecuted through Operation Streamline in Tucson. Dorame-Gonzalez was charged with one count of illegal entry and another count of illegal re-entry, a greater charge. In a process prosecutors call “flip-flop,” defendants in Operation Streamline with prior offenses can plead to a lesser charge and have the heavier one dropped.

Dorame-Gonzalez was sentenced to 60 days in prison with credit for time served.

Then, in November 2015, Dorame-Gonzalez was caught again, this time smuggling a group of six Middle Eastern men in southern Arizona.

The men had fled violence in their countries and were cleared of any ties to terrorism.

Dorame-Gonzalez pleaded guilty to a smuggling charge and was sentenced to over two years in federal prison.

Hugo Reyna, a federal public defender who has been working Operation Streamline hearings since they were adopted in Tucson nearly a decade ago, says the program isn’t an effective recidivism tool.

Reyna spoke on his behalf only.

He said attorneys start meeting with defendants at 9 a.m. and have until noon to prep with them. Reyna said most of his clients are farmworkers with limited education and no understanding of the American judicial system. Some are indigenous and don’t speak Spanish.

But in the nearly 10 years he’s been working with Operation Streamline, Reyna says he’s seen little change in migrant patterns.

“When we started here in 2008, it was 70 defendants that were being processed and charged. Today we’re still at 70. So as far as deterrent is concerned, maybe it’s not quite as effective as they had anticipated,” Reyna said.

___

Associated Press writer Elliot Spagat in San Diego contributed to this report.

.