The Trump administration should not "play politics with public safety", Johnson added.
"I think it is a smart lawsuit", said Mr. Villegas, whose ward was the site of a shooting this year involving an Immigration and Customs Enforcement agent that raised tensions among residents.
Chicago Corporation Counsel Ed Siskel said cities would have to give the feds 48 hours' advance notice of an arrestee's release, "which, in many cases, would require detaining individual residents longer than necessary for the sole objective of providing that 48-hour advance notice - in violation of their Fourth Amendment rights".
The 46-page lawsuit filed Monday says that "neither federal law nor the United States Constitution permits the Attorney General to force Chicago to abandon. critical local policy" on immigrants.
"Our police department is part of a neighborhood, part of a community, built on the premise of trust", the mayor said.
However, Emanuel said the conditions placed on applications for the Byrne Grant - due September 5 - amount to a "camel's nose under the tent", and if successful would certainly lead to additional punitive actions against sanctuary cities like Chicago.More news: CW to Air Supergirl and Arrow Crossover This Coming Fall
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Mayors like Mr Emanuel, however, have taken issue with the Trump administration's increased immigration enforcement activity.
If, as some fear, the order would threaten funding for cities which claim sanctuary status because they tell police not to question people about their immigration status, and don't honor detainer requests to hold people in jail for immigration purposes, it may be unconstitutional on several grounds. It was just two days after Emanuel received widespread attention for telling a veteran news reporter he planned to sue the Justice Department. If true, this could put a damper on the President's plans - or not.
In June, the House of Representatives voted to pass the "No Sanctuary For Criminals Act", by a 228 - 195 vote.
There's also a possibility of other sanctuary cities taking the city's side.
H.R. 3003, the No Sanctuary for Criminals Act, contains a section named for Sarah Root, killed by an illegal charged with drunk driving, and Grant Ronnebeck, who was murdered by an illegal alien and self-proclaimed Sinaloa Cartel member out on bail pending his removal.
The suit revolves around specific conditions Sessions announced in July for a federal program, the Edward Byrne Memorial Justice Assistance Grant, or Bryne JAG, which provides federal funding to support local law enforcement efforts. The Senate is expected to vote on the bill soon. Sessions' announcement is proof that the president is making good on his promise. They say Chicago police officers make no inquiries about immigration status because doing so might fracture residents' trust of the police and discourage those here illegally from reporting crimes or cooperating as witnesses, making the streets more unsafe. However, it is at the very least a step in the right direction.