The chief of police in Washington, D.C., will allow the Metropolitan Police Department to work with federal immigration authorities to arrest illegal immigrants, an unprecedented move that follows President Donald Trump’s crackdown on crime in the city.

The immigration agency must hold fewer detainees and provide them with medical care and regular access to lawyers, Judge Lewis A. Kaplan said.

A federal judge on Tuesday said he would block the Trump administration from using a federal building in New York City to hold immigrants facing deportation unless it reduces the number of detainees and improves conditions at the site,