By GISELA SALOMON and REBECCA SANTANA

As part of the Trump administration’s push to carry out mass deportations, the agency responsible for immigration enforcement has aggressively revived and expanded a decades-old program that delegates immigration enforcement powers to state and local law enforcement agencies.

Under the 287(g) program led by Immigration and Customs Enforcement, police officers can interrogate immigrants in their custody and detain them for potential deportation.

Since President Donald Trump took office in January, ICE has rapidly expanded the number of signed agreements it has with law enforcement agencies across the country.

The reason is clear. Those agreements vastly beef up the number of immigration enforcement staff available to ICE, which has about 6,000 deportation officers, as they aim to meet Trump’s goal of deporting as many of the roughly 11 million people in the country illegally as they can.

Here’s a look at what these agreements are and what critics say about them:

What is a 287(g) agreement and what’s the benefit to ICE?

These agreements are signed between a law enforcement agency and ICE and allow the law enforcement agency to perform certain types of immigration enforcement actions.

There are three different types of agreements.

—Under the “jail services model,” law enforcement officers can screen people detained in jails for immigration violations.

—The “warrant service officer” model authorizes state and local law enforcement officers to comply with ICE warrants or requests on immigrants while they are at their agency’s jails.

—The “task force model” gives local officers the ability to investigate someone’s immigration status during their routine police duties.

These agreements were authorized by a 1996 law, but it wasn’t until 2002 that the federal government actually signed one of these agreements with a local agency. The first agreement was with Florida’s Department of Law Enforcement.

“The benefit to ICE is that it expands the ability to enforce immigration law across multiple jurisdictions,” said John Torres, who served as acting director of ICE from 2008 to 2009.

Earlier in his career, he said, he was assigned to the Los Angeles jail and would interview any foreign citizen who came through the jail to see if they were in the country illegally. But if a jail has a 287(g) agreement with ICE it frees up those agents at the jail to do something else.

What’s going on with these agreements under the Trump administration?

The number of signed agreements has ballooned under Trump in a matter of months.

In December of last year, ICE had 135 agreements with law enforcement agencies across 21 states. By May 19, ICE had signed 588 agreements with local and state agencies across 40 states, with an additional 83 agencies pending approval.

Roughly half of the pacts are in Florida, where Republican Gov. Ron DeSantis recently announced the arrest of more than 1,100 immigrants in an orchestrated sweep between local and federal officials.

Texas, where Republican Gov. Greg Abbott has also allied himself with Trump on immigration, comes in second. Other states topping the list are Georgia and North Carolina.

A majority of the agreements are with sheriff’s departments, a reflection of the fact that they are largely responsible for running jails in America.

But other agencies have also signed the agreements including the Florida and Texas National Guard, the Florida Department of Lottery Services and the Florida Fish and Wildlife Conservation Commission.

The expansion of agreements “has been unprecedented in terms of the speed and the breath,” said Amien Kacou, attorney at the American Civil Liberties Union in Florida.

“ICE under the Trump administration has made a push in every state essentially to have them cooperate,” Kacou said.

So what are the concerns?

Immigrants, and their attorneys and advocates say these agreements can lead to racial profiling and there’s not enough oversight.

“If you are an immigrant, or if you sound like an immigrant or you look like an immigrant, you are likely to be detained here in Florida,” said Felipe Sousa-Lazaballet, executive director at Hope Community Center in Apopka, central Florida.

These concerns are especially acute over the task force model since those models allow law enforcement officers to carry out immigration enforcement actions as part of their daily law enforcement work.

Lena Graber, a senior staff attorney with the Immigrant Legal Resource Center which advocates for immigrants, said that the Obama administration phased out the task force model in 2012 after concerns that law enforcement organizations authorized under it were racially profiling people when making arrests.

The first Trump administration considered bringing back that model but ultimately did not, she said. Graber said using this model, the local law enforcement have most of the powers of ICE agents.

“They’re functionally ICE agents,” she said.

Rights groups say that in areas where 287(g) agreements are in place, people in the country illegally are less likely to reach out to law enforcement authorities when they’re victims of or witness to a crime for fear that authorities will turn around and arrest them instead.

“This is finding methods to terrorize communities,” said Katie Blankenship, an immigration attorney and co-founder of Sanctuary of the South. “They create immigration enforcement and local law enforcement which they are not trained or able to do in any sort of just manner.”

Federal authorities and local law enforcement agencies deny those critics and maintain that officers follow the laws when detaining people.

“There is no racial profiling,” said Miami Border Patrol chief agent Jeffrey Dinise at a recent press conference along with Florida and ICE officials. He explained that officers may stop cars after traffic violations. They run the tag plates through immigration systems and can see the legal status of the person, he said.

Torres also said that local law enforcement officers operating under 287(g) agreements aren’t “out on an island by themselves.” There’s a lot of coordination with ICE agents and the local law enforcement officers.

“They’re not asking them to operate independently on their own,” Torres said.

How does law enforcement join?

Law enforcement agencies nominate officers to participate in the 287(g) program. They have to be U.S. citizens and pass a background check.

On its website, ICE has created templates of the forms that law enforcement agencies interested in joining the program can use.

The training varies. According to ICE’s website, officers in the “task force model” must complete a 40-hour online course that covers such topics as immigration law, civil rights and liability issues. As of mid-March about 625 officers had been trained under that model, the website said, although that number is likely much higher now as law enforcement agencies are signing up regularly.

For the “jail enforcement model,” there’s a four week training as well as a refresher course. The Warrant Service Officer model requires eight hours of training.

Austin Kocher, a researcher at Syracuse University in New York who focuses on immigration affairs, said that training has always been a challenge for the 287(g) program. It’s expensive and often a strain on small departments to send them to a training center, so the training has gotten progressively shorter, he said.