When Mayor Bill de Blasio took office, he vowed to end the crisis of inequality that had created what he called New York’s Tale of Two Cities. Yet a new report argues that the city’s immigrant communities continue to be trapped by the social divides wrought by biased policing and oppressive immigration policies. Rights groups say the de Blasio administration is marginalizing immigrants by allowing federal authorities to use people’s past records in the criminal justice system to undercut their constitutional rights.

According to the report by Families for Freedom and New York University Immigrant Rights Clinic, the city’s collusion with immigration authorities has led to the unjust detention and deportation of noncitizens as the police and the feds blur the lines between Homeland Security and Zero Tolerance.

Generally, local authorities do not have to enforce immigration laws on behalf of federal Immigration and Customs Enforcement (ICE), but the Secure Communities Program (S-Comm) enables local and federal sharing of immigration and criminal databases. Once data from ICE, the FBI and local precincts are meshed together, federal agents can easily nab someone on an immigration charge and a criminal charge that counts as a “deportable offense.” This can conveniently result in someone being banished from the country without going through the normal criminal process.

So the promise to end the tale of two cities rings hollow to New York immigrants who live in legal limbo under the cloud of their conviction history. In one case of a Dominican Republic–born legal resident, documented in the report, a misdemeanor drug offense from over a decade ago placed him at risk of deportation and made him frightened to come forward to naturalize, or even to travel outside the city. But at the time, “nobody, including his defense attorney, had said anything about immigration consequences when he pleaded guilty.” He eventually managed, with the help of a lawyer, to have his old conviction vacated and changed to a non-deportable offense. But had he had a run-in with ICE earlier on—if his workplace had been raided or he got pulled over by a mean cop—he might have gotten kicked out of the country before getting his second day in court.

The endemic inequities in the city’s criminal justice system are worsening the problem, says Families for Freedom Executive Director Abraham Paulos. “A lot of us came to New York during the 1980s and ’90s, and that was at the height of the war on drugs,” Paulos tells The Nation. “So now you’ve got a whole population of green-card holders here, or even undocumented folks, that have these convictions [and are] essentially in limbo.” Typically, he explains, a green-card holder with prior crimes on her record—perhaps just the result of plea bargaining to avoid the trouble of a trial—may be frozen in a legal no man’s land, he explains, forever subject to deportation and barred from naturalization: “I can’t apply for citizenship, because I have a felony, I won’t get it. But…[at the same time] any contact that I have with the NYPD might get me into the detention and deportation system.”

The report, drawing on field research and government data, outlines various ways that ICE “detainers,” or requests for local authorities to hold immigrant arrestees temporarily on federal authorities’ behalf, erode due process for people with prior convictions. An ICE detainer can block someone from from posting bail, which constrains access to the social support networks and legal counsel that could help build their case. If the detainee seeks a hearing in state court to request post-conviction relief—a key tool for retroactively converting an unfair record—ICE, according to the report, will refuse to bring the person to court, preventing them from appearing before the judge. In addition, ICE can pre-empt post-conviction relief by just deporting someone immediately, often with the help of foreign embassies and consulates that authorize the removals. If removal proceedings are set in motion while a claim is pending, FFF says, “some state courts refuse to hear the post-conviction relief claims of noncitizens after ICE has deported them.”

(While we often hear about deportations of the undocumented, a conviction for many types of crime, including some drug offenses, can lead even to someone with a green card being subjected to a “mandatory deportation” process, though they are legally living in the United States.)

The Obama administration claims ICE authorities focus on “criminal aliens” and not ordinary, otherwise law-abiding undocumented workers. But advocates argue that ICE insidiously uses relatively minor offenses as grounds for deportation, and the cooperation of city police and jails shows that both local and federal systems are less interested in protecting public security than in fueling the machinery of immigrant removal.

According to Syracuse University’s TRAC data project, nationwide, ICE data from the fiscal years 2012 and 2013 show about half of the cases for which ICE requested a hold involved “no record of criminal conviction, not even a minor traffic violation.” Overall, just 14 percent were deemed a “serious” public safety threat.

A previous legal study shows that ICE apprehended more than 34,000 New Yorkers from 2005 to 2010, often through the notorious Rikers Island jail. The vast majority of these detainees were not offered a bond setting.

There has been growing pushback against ICE intervention, however. The New York City Council has placed some restrictions on ICE’s ability to detain undocumented immigrants in local custody. These build on two executive orders issued by Mayor Michael Bloomberg in 2003, which curtail sharing of immigration data between city agencies and ICE. Nationwide, three states, more than twenty cities and more than 150 counties have enacted measures to limit local compliance with ICE detainers. Still, New York City has continued to comply with most ICE detainers in recent years.

In a recent civil rights lawsuit in Oregon, a federal court ruled that the detention of an immigrant on the basis of an ICE detainer, without showing probable cause, violated Fourth Amendment protections.

Undoing the sticky bind between ICE and local government comes down to local political will. Activists argue that since ICE detainers are essentially voluntary agreements, New York, by cooperating with ICE holds, is complicit in violating immigrants’ rights, particularly if they were victims of a botched legal proceedings earlier.

A coalition of rights groups, including FFF, DREAMer youth activists and Black Alliance for Just Immigration, has launched the #ICEFREENYC campaign to demand that the de Blasio administration decisively cut ties with ICE to protect all New Yorkers’ civil rights. Pointing out that past reforms do not explicitly protect people with prior convictions, they want the mayor to “explicitly prohibit the NYPD, DOC, and any City agency from detaining New Yorkers at the request of ICE,” bar all information sharing with ICE, and keep ICE agents away from ”sensitive locations including hospitals, courts, homeless shelters, public demonstrations, community centers, places of worship and schools.”

In response to the campaign, the de Blasio administration has stated that city agencies, as a policy, will “protect the confidentiality” of immigrants while “ensuring that people are not put on the path to deportation for minor violations.”

In written comments to The Nation, Commissioner of the Mayor’s Office of Immigrant Affairs Nisha Agarwal says: “Deportations create instability in our communities, and revising New York City’s stance on detainer requests was in the Mayor’s platform from the get-go. We are reviewing the current policies.”

Meanwhile, Paulos, who himself got swept into detention a few years ago while stuck with past convictions from his teens, warns that ICE “has been running rogue in New York City, and has been able to use the criminal justice system as a scapegoat and as a pipeline.” And local agencies are “going through all types of problems from law enforcement down to the courts.… The last thing you want to do is voluntarily bind these systems together.”

The insidious complicity between immigration and criminal law enforcement shows that while they claim to embrace the city’s newcomers, local policymakers still display more allegiance to Washington’s border hawks than respect for the rights of New Yorkers.

Editor’s note: Read a response from the Office of Mayor Bill de Blasio about the administration’s record on immigration enforcement reform.