U.S. District Judge Dana Sabraw in San Diego set a deadline of last Thursday to reunite the families. While he commended administration officials for reuniting many parents in its custody with their children, it faulted them for leaving hundreds of families still apart and warning that a better system must be in place. The senators’ letter, based on articles by The Associated Press and other news organizations, says the allegations suggest “a long-term pattern” of mistreatment. Those reports describe claims of abuse from this year dating back to before Trump took office and include accusations of sexual and other forms of assault at some facilities. The AP reported last month that children held at an immigration detention facility in Roanoke, Virginia, said they were beaten while handcuffed, locked in solitary confinement and left nude and cold in concrete cells. A civil rights lawsuit has been filed alleging mistreatment at the Shenandoah Valley Juvenile Center from 2015 to 2018. The alleged victims, Hispanic youths held for months or years, have submitted sworn statements in the case. Lawyers for the facility have denied the alleged abuse. Alan Fram, The Associated Press Washington correspondent Rachel Cohrs contributed to this report.