One night in May, 2015, an accountant named Renata Singleton arrived home from work and changed into lounge pants. Singleton, a polite, bespectacled woman in her mid-thirties, who kept the books for a local New Orleans charter school, intended to have a quiet evening with her three children. She was surprised when two uniformed police officers knocked on the door. “Can we speak to you away from your kids?” one of the cops asked. Singleton stepped outside to join the officers and recalls one of them explaining, “The district attorney’s office called us to come and pick you up tonight.” The officers had a warrant to arrest Singleton and take her to the Orleans Parish Prison. Singleton had not committed—nor even been accused of—a crime. But, six months earlier, she’d called the cops after her then boyfriend, in a jealous fit, grabbed her cell phone and smashed it; she’d feared for her safety. The cops had arrived and arrested the boyfriend. Later, Singleton told the district attorney’s office that she wasn’t interested in pursuing charges. (She’d left the relationship in the meantime.) Still, the D.A.’s office pressed ahead. Her ex faced charges of “simple battery and criminal damage to property less than 500 dollars,” and prosecutors wanted Singleton to testify against him in court.

Now, the cops had a warrant to arrest Singleton because, according to the D.A.’s office, she had dodged the office’s attempts to serve her a subpoena or contact her by phone; according to Singleton, a prosecutor wanted to interview her about the alleged crime in private and had deemed her an uncoöperative victim. (Singleton told me that she had planned to appear in court; she’d ignored two previous subpoenas left in her door, which were improperly served.) The D.A.’s office was using an arcane tool of the law—a little-known but highly consequential instrument called a “material witness” statute—to jail Singleton until she testified in court about the cell-phone incident.

While the officers were at Singleton’s home, a friend who worked in law enforcement arrived and told the officers, “Don’t do this! The kids are in the house—you’re going too far!” She promised to escort Singleton to the D.A.’s office in the morning, after arrangements could be made for the children.

The next day, as promised, Singleton met with an assistant district attorney, Arthur Mitchell, who questioned her about her evasiveness and pressed for details on the domestic-violence incident. (His office, he claimed, had visited her house and place of employment on numerous occasions, hoping that she would talk.)

“I need a lawyer,” Singleton said.

“You’re the victim,” Mitchell replied, according to Singleton. “You don’t get a lawyer.”

“Well, right now I don’t feel like the victim,” Singleton responded. As an officer came to arrest her, putting her in handcuffs and escorting her to a police car, Singleton thought about her son and daughter—ages ten and fifteen—who were expecting to see their mom after school.

“Please,” Singleton said to the officer. “How will I explain this to my kids?”

Across America, some prosecutors—arguably with the authority of state and federal laws—are jailing innocent crime victims and witnesses, in hopes of insuring their testimony in court. In Washington State, a sexual-assault victim was arrested and jailed to secure her testimony against the alleged perpetrator. (He was found guilty of kidnapping, attempted rape, and assault with sexual motivation.) In Hillsboro, Oregon, a Mexican immigrant was jailed for more than two years—nine hundred and five days—to obtain his testimony in a murder case. (The case was being brought against his son.) And in Harris County, Texas, a rape survivor suffered a mental breakdown in court while testifying against her assailant. Afraid that the woman would disappear before finishing her testimony, the court jailed her for a month. She has since filed a federal lawsuit against the county and several individuals involved, alleging that she was “abused, neglected, and mentally tortured” while in detention.

The right to jail these so-called material witnesses has deep roots in America. (A material witness is an individual considered vital to a case, often because he or she saw a crime unfold or was its victim.) As early as 1789, the Judiciary Act codified the duty of witnesses to appear before the court and testify. From a public-safety perspective, the statute has a clear purpose: the perpetrator of a crime should not escape punishment because of a witness’s reluctance to testify. “The duty to disclose knowledge of crime rests upon all citizens,” a 1953 U.S. Supreme Court opinion, in the case Stein v. New York, reads. “It is so vital that one known to be innocent may be detained, in the absence of bail, as a material witness.” In 1984, Congress reaffirmed the right to jail material witnesses, but also noted that their testimony should be secured by deposition, rather than imprisonment, “whenever possible.” Jailing crime survivors and innocent witnesses, in other words, was legal but undesirable.

After the attacks of September 11, 2001, Attorney General John Ashcroft identified the material-witness statute as a convenient weapon for the war on terror. Federal agents could use it to detain individuals of interest, even without sufficient evidence to arrest them as criminal defendants, by deeming them “witnesses” to terrorism-related crimes. In late 2001, the Department of Justice used material-witness laws to target Muslims, often arresting them at gunpoint and later placing some in solitary confinement. According to Human Rights Watch, the U.S. government eventually apologized to at least thirteen people for wrongful detention as material witnesses, and released dozens more without charges. “Holding as ‘witnesses’ people who are in fact suspects sets a disturbing precedent for future use of this extraordinary government power to deprive citizens and others of their liberty,” Human Rights Watch argued. In the face of lawsuits and public scrutiny, the practice slowed.

Recently, however, controversy over the use of material-witness statutes has resurfaced—this time at the state and local level. In parts of the country, prosecutors are using these orders to put crime victims—especially poor victims, and, in cities like New Orleans, victims of color—in jail in order to get swift victories in court, sometimes, puzzlingly, in minor cases. A lawsuit filed today in federal court by the American Civil Liberties Union and Civil Rights Corps, a legal nonprofit based in Washington, D.C., seeks to challenge what it calls “the Orleans Parish District Attorney Office’s unconstitutional policy of using extrajudicial and unlawful means to coerce, arrest, and imprison crime victims and witnesses.” The suit alleges that the office’s practices “ensure these victims and witnesses are trapped in jail.”

Despite the public attention given to prosecutorial misconduct in recent years, this form of alleged abuse has gone mostly unnoticed. Last spring, a watchdog group called Court Watch NOLA released a report documenting attempts by the office of the Orleans Parish D.A., Leon Cannizzaro, Jr., to coerce testimony from crime survivors. The lawsuit filed today, on behalf of Singleton and other plaintiffs, questions the justifications that prosecutors have used to put victims and innocent witnesses in jail. According to the complaint, prosecutors sought more than a hundred and fifty material-witness warrants over the past five years in Orleans Parish; approximately ninety per cent of the victims and witnesses, in cases where the A.C.L.U. could determine race, were people of color. Poverty, homelessness, precarious immigration status, and mental-health issues were all invoked by the D.A.’s office as reasons to jail crime victims, who included survivors of sexual assault, domestic violence, and child sex trafficking.