Many county and municipal governments in Pennsylvania, including some in the Philadelphia suburbs, use their local manpower to actively assist federal immigration agents, often alerting those authorities to undocumented migrants in their custody, according to a study released Tuesday.

The study cited 19 counties that had either formal contracts with ICE to hold migrants; shared jail information; provided jail access to federal agents; supplied times that ICE could pick up a migrant; had the probation office work with ICE; or wished to pursue a stronger relationship with the agency.

Chester County checked five of those six boxes — it has no detention contract with ICE — tying for first among the surveyed counties for greatest cooperation with the agency. Officials there could not immediately respond to a request for comment.

Bucks and Montgomery Counties each checked three, as did Delaware County, the only one of the suburban counties with a detention contract.

The alliances between ICE and local authorities result in migrants being detained and turned over to federal authorities even where “sanctuary” policies are in place, the study said, adding that some county jails share information with ICE every week and even every day.

“There is definitive proof of local police and ICE collusion across Pennsylvania,” Juntos spokesperson Miguel Andrade said on Tuesday.

ICE officials issued a statement in response, saying that some local officials have created policies that “hinder cooperation between ICE and local law enforcement.

“Despite these impediments, ICE is committed to enforcing the immigration laws set forth by Congress with integrity, and will continue to work with our local, state, and federal law enforcement partners to identify, arrest, and remove criminal aliens from our communities,” the statement said.

Since President Donald Trump took office, deportation officers have been freed from an Obama-era mandate to focus on removing immigrants with serious criminal convictions, making almost any undocumented migrant a potential target.

Nowhere have federal agents more aggressively embraced that freedom than in the Philadelphia field office, which covers Pennsylvania, West Virginia, and Delaware, an investigation by ProPublica and The Inquirer found.

The “sanctuary city” of Philadelphia, home to about 50,000 undocumented immigrants, expressly declines to help ICE find and arrest undocumented migrants, saying that would erode community-police cooperation and prevent people from coming forward as victims or witnesses of crimes. Enforcing immigration law is the job of federal officers, not local police, city officials have said.

The city demands that ICE provide a signed judicial warrant — not a detainer signed by an administrative employee — before it will turn over someone in custody.

The study was released at a news conference Tuesday, where Juntos and Sheller Center leaders were accompanied by members of Vietlead, Victim/Witness Services of South Philadelphia, and other immigrant-rights organizations. The study did not include information on New Jersey jurisdictions.

The study authors gathered evidence by filing Right-to-Know requests, speaking with local officials, and reviewing Freedom of Information Act documents recovered by other organizations.

They found that county jails and probation departments regularly share information with ICE as part of informal agreements or written policies. Municipal police cooperation, on the other hand, has been mostly ad hoc, creating openings for individual officers to act based on their personal inclinations, and for ICE to pursue greater assistance from officers and departments.

The study said probation officers in Pennsylvania often seek to lure migrants to meetings, where ICE will arrive and make an arrest. It provided an excerpt of a May 2018 email conversation between an ICE agent and a Delaware County probation officer, in which the two worked to persuade a migrant woman to come to such a meeting.

“We’re going to need to set another date to take [redacted] into custody,” the ICE officer wrote. “I apologize for the late notice, but is there any way we can work out something for her next report date, possibly in about a month?”

The probation officer replies that it’s “going to be hard to keep making excuses for her to come in as we have transferred her case to Philly," adding, “Sooner or later she is gonna figure this out.”