A federal judge yesterday said she will rule next month on a petition to release a Guantanamo Bay detainee, saying the government appears to have no case and, at points, criticizing what she called delaying tactics by the Department of Justice.

Judge Ellen Huvelle made that announcement in the U.S. District Court in Washington a day after government lawyers decided not to challenge a motion to throw out a confession by Mohammed Jawad, an Afghan man whose lawyers say confessed under torture to having thrown a grenade at U.S. troops seven years ago.

Mr. Jawad's case was the spark that led to the resignation of an Army prosecutor who later told the House Judiciary Committee he believed the confession was obtained under torture and that the system of military commissions set up to try persons detained in the wake of 9/11 was beyond repair.

Darrel Vandeveld, a state prosecutor from Erie and an Army reserve officer, resigned as a prosecutor after he became convinced that Mr. Jawad's statements were obtained by force and were likely untrue. He also became convinced that Mr. Jawad was only 14 years old at the time he was seized.

The Afghan government has since issued a declaration that it believes Mr. Jawad was 12 when he was captured. He has been in custody for the past seven years.

"He's a nobody. He is at the very most a recruited child foot soldier. But even the evidence of that is very sketchy," said David Frakt, a California law professor and Air Force Reserve legal officer who represented Mr. Jawad before the commissions.

A military judge in Guantanamo earlier had ruled Mr. Jawad's statements inadmissible in a criminal prosecution because they were obtained under physical duress. Since that time, his lawyers had pressed for his release from custody.

"They're continuing to hold him. We believe there's really no evidence left and there's certainly no basis to hold him, and we're going to be moving for a rapid disposition in the result of his case," said Jonathan Hafetz, the ACLU attorney who brought a habeas corpus petition on Mr. Jawad's behalf after his military commissions prosecution foundered.

While the prosecution now appears stalled, that is no guarantee Mr. Jawad will be released. Other detainees have remained in custody at Guantanamo after prosecutions failed or were abandoned.

Dean Boyd, a Justice spokesman, said yesterday that the prosecution's decision in the Jawad case was not a forerunner to similar decisions on other detainees. Despite a campaign pledge to close Guantanamo, the Obama administration has faced a dilemma in whether to attempt reforms to the military commissions system and what to do with some detainees who might be in danger if returned to their countries of origin.