Top U.S. Department of Justice and immigration officials should face legal scrutiny for the unconstitutional detention and torture of Muslims living peacefully in the U.S. in the wake of the 9/11 terror attacks, Americans United told the U.S. Supreme Court Tuesday.

In a friend-of-the-court brief, Americans United, joined by the People For the American Way Foundation, asked the high court to allow a suit to proceed against former attorney general John D. Ashcroft, former FBI director Robert Mueller and former commissioner of the U.S. Immigration and Naturalization Service James W. Ziglar.

“This case comes to the Court at a time when anti-Muslim sentiment is on the rise,” Americans United wrote in the brief. “Private discrimination and harassment are all too common. When, as here, that discrimination becomes government-sanctioned, government-sponsored oppression, it is all the more intolerable.

“Thus, not only is it critical that the victims of that oppression have the opportunity to seek judicial remedies for the injuries and indignities that they suffer at the government’s hands, but it is paramount that this Court send a strong message that official disfavor and the meting out of punishment on the basis of religion are antithetical to our constitutional order,” AU stated.

The Supreme Court in October agreed to hear arguments in three consolidated cases, now called Ziglar v. Abbasi. The cases were filed more than 14 years ago by the Center for Constitutional Rights on behalf of people who were caught up in the United States’ efforts to combat terrorism.

As noted in Americans United’s brief, the Department of Justice initiated a “massive investigation” to track down possible terrorists and to investigate the tens of thousands of terrorism-related tips fielded by the FBI immediately after Sept. 11, 2001.

As part of the investigation, Ashcroft and Mueller oversaw a broad policy to crack down on even trivial immigration violations committed by Muslims and those perceived to be Muslim or from Arab countries.

Many of the detainees were held for months in solitary confinement at New York City’s Metropolitan Detention Center, officials from which also have been targeted in one of the lawsuits.

The U.S. should not have targeted Muslims for solitary confinement and torture based on their religion.

While at the facility the detainees were subjected to physical and psychological abuse – from beatings and sleep deprivation to denial of basic necessities and their right to file complaints over their treatment. They also were deprived of the ability to practice their faith, including denial of requested copies of the Koran and halal food. They weren’t even allowed to know the time of day so they could say their prayers.

“Two former MDC lieutenants have since frankly admitted that ‘some officers took their anger and frustration about the September 11 terrorist attacks out on the detainees,’” AU’s brief notes.

While the detainees had been arrested nominally for violating immigration law – typically they were accused of either entering the U.S. illegally or staying beyond the time allowed by their visas – AU contends they were treated differently from others who had committed similar infractions. Their detention and maltreatment continued even after they were cleared of any terrorism-related activities.

Because these detainees were singled out due to their perceived religious affiliation, AU makes the case that the actions of U.S. officials violated their right to practice their religion freely, as guaranteed under the First Amendment, and the constitutional right to equal protection of the laws.

“To put it plainly, any reasonable law enforcement official – and even unreasonable ones – should have understood in 2001 that is unconstitutional to round people up, incarcerate them, place them in solitary confinement, harass and abuse them, and deny them the ability to worship and practice their faith, even after determining that they are not a security threat … all based on the detainees’ adherence to a disfavored religion and associated ethnicity,” AU’s brief asserts. “(I)t is long and clearly settled that the Establishment Clause forbids singling out a religious group for disfavor and that the Free Exercise Clause forbids punishing based on religious affiliation or  belief.”

After a federal appeals court agreed to let the case move forward in June 2015, Ashcroft, Mueller and Ziglar asked the Supreme Court to hear the case to determine, among other legal issues, whether they are entitled to qualified immunity (which would mean they cannot be held liable for damages for the harms to the detainees) and whether they were involved enough in the detainees’ treatment to be included in the case.

Americans United asks the Supreme Court to affirm the lower court’s ruling and allow the cases to be heard on the merits. Arguments before the high court are scheduled in January.