It wasn't much of a case: Queens prosecutors wanted to prosecute a woman for having falsely reported her car stolen in a bid to collect on theft insurance. A non-violent crime. Small-time really.

But the prosecutors went to unusual lengths in 2008 to try and make the case. They tracked down a person they thought had information about the alleged fraud, told her she was under arrest, and over the course of two days interrogated her in a room in the Queens District Attorney's office. The woman, Alexina Simon, was not a suspect. She was, in truth, nothing more than a potential witness.

Today, Simon is the named plaintiff in a federal case that has reached the U.S. Court of Appeals for the Second Circuit. The case is noteworthy for two reasons:

It shines a light on the issue of what are known as material witness orders, a poorly understood aspect of New York's criminal justice system in which people who are potential witnesses to crimes can be detained, evaluated and perhaps compelled to disclose what they know.

The case is also seeking a remedy that those concerned about misconduct by the country's district attorneys have long sought, namely that individual prosecutors be held personally liable for their misdeeds.

Lawyers for Simon have argued that the prosecutors in the case failed to do what is required when such material witness orders are granted by a judge — bring the witness before that judge and make sure that witness has a lawyer. Simon, they say, had no meaningful information about the alleged fraud. That might have been sorted out had proper procedures been followed, they say. In all likelihood, they suggest, prosecutors not only would have figured out that she had no information, but also that she, owing to a mix up in names, was not the person they were actually looking for.

Instead, Simon says she was detained twice — arrested first at work and then at home the following day — and questioned for hours without a lawyer.

Lawyers for the Queens prosecutors have insisted Simon willingly cooperated and thus the warrant they had obtained, and the requirements that came with it, didn't apply. They argue further that, even had the prosecutors erred, they were, under the law, immune from being held personally liable for their misconduct.

A district court judge ruled for the prosecutors, holding that the broad protections given to law enforcement officials as they pursue cases applied in this instance. But the case was appealed, and since then, a brief has been filed by the U.S. Department of Justice in support of the district court's ruling and another has been submitted by defense lawyers in opposition. A decision is expected soon.

The issue of the use and misuse of material witness orders came under scrutiny after 9/11. Federal authorities used the warrants to lock up any number of people they suspected might have information about terror investigations. A subsequent lawsuit that sought to hold former U.S. Attorney General John Ashcroft personally liable for the abuse of material witness orders made it to the Supreme Court, which held that Ashcroft was immune.

The use of material witness warrants in state cases has garnered far less attention and the Simon case has to date been a relatively obscure one. But a lawsuit brought by a man who says he was wrongly prosecuted for murder could give the use of material witness warrants in state prosecutions an explosive airing.

Lawyers for Jabbar Collins, who spent 16 years in prison before prevailing in a rare federal petition for his freedom, have accused Brooklyn District Attorney Charles J. Hynes of running what amounts to his own civil jail system. Collins's lawyer, Joel Rudin, has charged in court papers that he has evidence Hynes's office routinely and illegally detained witnesses to compel and sometimes coerce testimony.

Hynes's office has denied the assertion.

For Rudin and other defense lawyers, the misuse of such warrants — locking people up until they tell a story the prosecutors need told to make a case — could be a central cause of the kinds of wrongful convictions that, again and again, have been uncovered across the country in the last decade or so. And they argue that the problem is not likely to be corrected unless prosecutors can be held personally responsible.

The abuse of such warrants, Rudin wrote in a brief that is part of the Simon case before the appeals court, "threatens the rights of individuals held as material witnesses to prompt arraignment, representation by counsel, and an independent determination of their status." Granting prosecutors immunity when they abuse the warrants, he wrote, "would deny aggrieved individuals any compensation or other remedy for their constitutional injuries and would encourage law enforcement authorities to continue such practices."