In a 48-page rejection of the Justice Department's motion for dismissal, U.S. District Judge Ann Aiken also ordered the FBI to open up files showing how agents secretly spied on Mayfield and his family.

Federal law enforcement officials had released some details of the so-called sneak and peak searches of the family's home in the spring of 2004.

However, Mayfield's attorneys have argued that they can't adequately proceed with their challenge to the constitutionality of the Patriot Act without total access.

The federal judge agreed.

Aiken wrote that Mayfield's family is "entitled to the opportunity to determine the nature of the surveillance and searches conducted, and a specific description of the data and documents collected."

The case is being closely watched across the country as a chief test of the constitutionality of the Patriot Act.

In May 2004, a botched FBI analysis of a fingerprint mistakenly linked Mayfield to last year's deadly terror attack in Madrid, Spain. The Portland attorney was jailed for two weeks as a material witness before he was exonerated and received an apology from the FBI.

Mayfield's lawsuit claims agents targeted Mayfield because he is Muslim.

Although Mayfield suspected authorities had conducted sneak-and-peek searches of his home under the Patriot Act, the federal government didn't acknowledge it until earlier this year.

During a July 15 hearing in U.S. District Court in Portland, the government asked the judge to dismiss Mayfield's challenge to the Patriot Act, which broadened the Foreign Intelligence Surveillance Act of 1978.

The act allows federal agents to collect information on suspected terrorists, and the Patriot Act permits that information to be used in criminal prosecutions.

Mayfield attorney Elden Rosenthal said Aiken's ruling showed that she saw through "the government's effort to stonewall" his client's claims.

"We are, of course, pleased that Judge Aiken has ruled that the wrongs committed against Mr. Mayfield and his family are legitimate legal claims," Rosenthal said.

Although Rosenthal acknowledged that the ruling was far from a rejection of the Patriot Act itself, he said it removed major barriers preventing him from arguing Mayfield's case.

Until now, Rosenthal said Mayfield and his family could only guess how government agents acted, what they seized and with whom the information was shared.

"It opens the door for us to find out what really happened so (Aiken) can address the issue of the Patriot Act," he said.

"She is saying, 'Enough of this secrecy stuff. Either give this to the plaintiffs or give it to me.' "

Government officials have said they are in the process of collecting all of the information pertaining to the Patriot Act searches and wire taps used on Mayfield.

During this month's hearing, government lawyers repeatedly acknowledged that Mayfield was the victim of a mistake. They said they regretted the hardship it caused him and his family.

But they argued that mistake does not mean the government should be required to disclose its spying techniques and tactics. Those things deal with national security and should be kept secret, even when their target is found to be innocent, they said.

"We've not had a chance yet to review the judge's ruling, so we'll decline further comment at this time," said Tasia Scolinos, U.S. Department of Justice spokeswoman.

The ruling, which was released shortly after 4 p.m. Thursday, also denied the government's motion to dismiss Mayfield's claim for monetary damages on the grounds that federal law provided immunity.

The judge also refused to remove from the lawsuit the individual fingerprint analysts who made the identification. Mayfield's attorneys, she said, "have raised serious issues surrounding the validity of those fingerprint matches."

Justice Department lawyers have said the fingerprint misidentification was reasonable and not malicious. They have argued that the analysts and the agent who wrote a sworn statement that was the basis for a search warrant of Mayfield's home did not mislead or lie to the court.

But even before Mayfield was arrested, Spanish authorities were challenging the FBI's identification of the fingerprint.

The fingerprint analysts "argue that they cannot be held liable for . . . alleged falsehoods and omissions in the affidavits," the judge wrote. "I disagree."

"A law enforcement officer who knowingly supplies false information, or knowingly omits relevant information, to another officer who then drafts an affidavit based on that information is liable to the injured citizen."