Rod Rosenstein, the former deputy attorney general, advised US attorneys implementing the 2018 zero-tolerance policy that there could be no blanket ban on prosecuting migrant parents who had children under the age of five.

At a hearing Monday, Judge Mary Ellen Brennan denied a motion to release a 15-year-old from a juvenile facility. “I think you are exactly where you are supposed to be,” Brennan said. “You are blooming there, but there is more work to be done.”