The New York Civil Liberties Union sued a federal agency Thursday for documents about its role in a grant program allegedly designed to "find, arrest, detain, and deport unaccompanied immigrant children." The lawsuit alleges that the Office of Refugee Resettlement (ORR), which is not a law enforcement agency, may have shared information with police that has facilitated the detention of unaccompanied migrant children released by the agency to relatives in the U.S.

ORR oversees child care for thousands of unaccompanied migrant children. The lawsuit alleges that a federal grant program encourages local police departments to learn from ORR who the unaccompanied migrant children in their jurisdictions are, and in return to tell federal authorities if the children might be designated "gang associates."

Attorneys wrote in the complaint that they requested documents from ORR as part of a Freedom of Information Act request in August, and have not received a response. A spokesperson for the agency said it does not comment on pending litigation.

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The grant program, "Gang Suppression: A Law Enforcement and Prosecutorial Approach to Address Gang Recruitment of Unaccompanied Alien Children," has provided $4.8 million to police in four counties across the country, requiring them to develop gang enforcement strategies that lawyers said explicitly target unaccompanied migrant children.

The grant is part of U.S. Immigration and Customs Enforcement's "Operation Matador." NYCLU lawyers alleged that the operation "allows federal immigration enforcement agents, in coordination with local law enforcement partners, to designate any immigrant child a 'gang associate' based on as few as two indeterminate criteria, such as frequenting a known 'gang hangout,' which could be any location, or wearing 'gang colors,' like blue."

Senator Jeff Merkley, an Oregon Democrat who is a frequent critic of the Trump administration's immigration policies, called on ORR to release any documents it has about Operation Matador.

"I'm deeply disturbed by reports that the agency responsible for taking care of vulnerable unaccompanied children is instead facilitating deportations, often on flimsy accusations of gang affiliations. Let's be clear: Children are fleeing horrific violence in Central America, and ORR has a moral and legal responsibility to act exclusively in their best interest while they are in ORR's care. I'm calling on ORR to immediately release the requested records so everyone can see and understand the true nature of this program," Merkley said in a statement to CBS News.

The lawyers claim that as of December 2018, 170 unaccompanied migrant children had been rounded up as part of the program, and detained in some cases "on the basis of such trivial things as possessing drawings of their high school mascot or the area code for their home country, both of which ICE characterized as 'gang paraphernalia.'"

Children detained as part of the program are held in so-called "secure facilities," jail-like buildings intended only for those at risk of harming themselves or others. A recent study by a different group of attorneys, partnered with researchers from Stanford University, found the average length of stay for children in secure facilities is more than six months.

Their report included testimonials from children in the facilities.

"I sleep in a locked jail cell. The beds are thin mattresses on top of a block of cement and we don't get pillows. I have a make-shift pillow that I make out of my sweaters or other clothes," one child wrote, according to the report. "The guards also push us, pepper spray us, and place the handcuffs excessively tight – to the point that wrist injuries frequently occur."