Editor's note, Oct. 29, 2013: This story has been updated from its original version to improve clarity.

Traffic operations designed to catch unlicensed drivers are provoking allegations of racial profiling across the Delaware Valley. The concerns stem from ICE officers working hand in hand with local police, which immigrant rights advocates say is an end-run around state and federal law specifically prohibiting police from enforcing immigration laws.

Last June, Benjamin married his longtime girlfriend before a justice of the peace in the morning, with their three children — all American citizens like his wife — as their audience.

That afternoon, their eldest daughter, then still a toddler, was with Benjamin in his car as he rolled up to a traffic checkpoint.

ICE and police work closely at traffic checkpoints

Benjamin can't get a license, because he arrived in the country illegally 11 years ago. The trooper marked an "X" on the windshield and directed him into a parking lot that would fill with Hispanic drivers and passengers that afternoon. On this and one other occasion, there were also officers from Immigration and Customs Enforcement, or ICE.

The recently retired chief of police, Russell Bono claimed his officers did not help with immigration enforcement, stating emphatically that, "we were not involved in that at all. That was strictly ICE agents."

However, Benjamin, and a dozen others I tracked down who went through the checkpoints, indicated that Norristown police did send some drivers — but not all — to speak with ICE officers after writing their tickets.

Benjamin says they told him, "You go to the guys with ICE who check your prints, and maybe send you back to Mexico."

He says police tried to separate him from his daughter, telling him to call his wife to pick up his daughter. He refused.

Local police say they hold checkpoints regularly because of a persistent problem with people driving without the proper paperwork: license, registration, insurance.

But attorneys for some of the drivers suggest they may have been targeting something else. A post-industrial town, Norristown has problems with poverty and crime, including some Mexican gangs involved with drugs. An ICE report says police singled out possible gang members.

Of almost 100 drivers the Norristown police ticketed at checkpoints held with ICE, 60 percent had Hispanic surnames. For comparison, the last census found that Norristown was less than 30 percent Hispanic.

In the case of Benjamin, after a lengthy interrogation, ICE agents let him and his daughter walk away, but not others — including people who say they had nothing to do with any gangs.

Former chief Bono maintains that ICE worked alone, and that they used their authority sparingly.

"I could tell you there were probably 50 or more people who walked away who I know for a fact were not legal residents," the chief said.

Asked how he knows, he said simply, "I know."

ICE has specifically laid out its priorities. In 2011, word came from Washington to focus scarce resources on deporting immigrants who threatened public safety or repeatedly violated immigration law. The policy was called "prosecutorial discretion."

ICE points to cases such as that of Benjamin, the man who was let go, to show they exercised "prosecutorial discretion" in the field.

They stopped a Brazilian driver who had left his wallet at home and could not produce identification who says he had never been deported or accused of a crime.

The Brazilian, who asked not to use his name because he's fighting deportation, describes being held in the police garage with a group of Hispanic men, including one taken out of a truck belonging to his employer, a landscaping business.

"[His] wife went to get her three girls ... six, eight, 10 years old, to bring to him just to say bye and because, she says, they just want to give him a hug," recalls the Brazilian. "[ICE officers] say, 'You have nothing to do here.' He was in chains. He start[ed] to cry. It was so sad."

"All night I was thinking thousands of things in the jail. I come to achieve my goals ... [When] I woke up, I hoped it was a nightmare," he said.

Immigration attorneys allege that when ICE gets involved with daily traffic enforcement, they are bound to detain people that the agency says are not a priority.

Philadelphia's ICE office participated in traffic checkpoints in 10 locations last year. Immigration officers have taken part in similar operations in Georgia, North Carolina and California. ICE's Atlanta office listed checkpoints last year as one method to bump up quotas from Washington. They had targets to meet for criminal alien removals, according to documents obtained by the ACLU of North Carolina.

ICE ride-alongs combine separate jurisdictions

In Bensalem, Pa., immigration agents have done ride-alongs with individual cops. A driver originally from Ecuador says a police car pulled him over as soon as he turned out of his apartment's parking lot and asked for his driver's license.

"I said I didn't have one," said the driver.

The Ecuadorian can't get a license because he's in the country illegally. He didn't want his name used. He lives in the cheaper, less-dangerous suburbs of Philadelphia and drives to his landscaping work sites.

The Bensalem policeman gave him a ticket and then told him not to leave. "The man in the passenger seat got out of the car and came and tapped on my window," the driver explains in Spanish. "But this wasn't a police officer. He was from immigration."

The immigration officer arrested the driver. The lawyer helping the Ecuadorian fight his deportation in immigration court, Philippe Weisz, of non-profit immigration services organization HIAS Pennsylvania, points out that his client has no criminal history or prior deportation.

"Immigration joining local police in a ride-along to stop someone for driving without a license — that seems to exactly contradict immigration law enforcement priorities," says Weisz.

The head of the Philadelphia enforcement and removal operations, Thomas Decker, defends his officers' work with police departments:

"Our relationship with local law enforcement focuses on smart, effective immigration enforcement."

But attorney Weisz also points out that, except in special circumstances, Congress and individual states have kept local law officers out of enforcing federal immigration law. He explains that's both because police don't have the training and that policymakers recognize seeing police enforcing immigration law could deter immigrants from reporting crimes or cooperating with investigations.

Bensalem's head of public safety, Fred Harran, believes that local officers' collaboration with ICE improves public safety.

"If you get people in country illegally involved in negative activity, it's a great tool to use. And why not use every tool that is at our disposal?"

At least some have come to disagree. Norristown, the Pennsylvania town that ran the checkpoints last summer, did not invite ICE back this year.

This story was reported in partnership with the Investigative Fund at The Nation Institute with additional support from the Fund for Investigative Journalism.