DENVER -- The Colorado Supreme Court says Weld County authorities violated privacy rights of immigrants when sheriff's deputies seized thousands of tax returns to investigate them for identity theft.

The Court's Monday ruling affirmed a decision by a Weld County District judge who suppressed evidence against one of the defendants. That judge said authorities had no probable cause to search the man's tax returns and that the documents are confidential.

The tax returns of Ramon Ricardo Gutierrez were seized from the offices of his tax preparer and showed that Gutierrez reported income from work that he performed while using someone else's social security number, according to court records. Gutierrez then was charged with identity theft and criminal impersonation.

Gutierrez's file was one of about 5,000 client files seized from Amalia's Tax and Translation Services in Greeley, Colo. The trial court found the search warrant used to obtain the files was invalid because it did not provide probable cause to believe that Gutierrez's client file contained evidence of a crime. The search warrant affidavit did not name Gutierrez or refer to him in any way.

The district attorney and the Weld County Sheriff's Office called the investigation "Operation Numbers Game," and the trial court described the search as "extraordinarily wide-sweeping" and concluded that it was "an exploratory search" designed to permit the sheriff to rummage through "the confidential records of thousands of people based on nothing more than a suspicion that one or more of them may have committed a crime."

The Supreme Court justices agreed, saying that to rule otherwise "would permit state law enforcement to circumvent the Fourth Amendment as well as a complex federal statutory regime designed to protect taxpayers' privacy."

"A taxpayer has a reasonable expectation of privacy in his or her tax return and return information, even when that information is in the custody of a tax preparer" according to the Supreme Court ruling.

The Colorado Immigrant Rights Coalition praised the Supreme Court ruling, saying Weld County’s attempt to enforce federal immigration law was “wrong-headed, costly and did great damage to the community.” The Coalition also said the cases “demonstrates why we need solutions to our broken immigration system.”

"Today's ruling confirms Operations Number Games to have been an egregious abuse of power by Weld County officials,” the Coalition said in a prepared statement. “Paying taxes is not a crime and should not be made to seem like one. Rather, it is what the U.S. government asks of its residents. Those targeted had their privacy rights violated. The ruling goes to show that the Constitution protects the basic rights of all U.S. residents, regardless of suspected immigration status.”

The defendant was one of more than 70 people charged with criminal impersonation and identity theft. Some other defendants pleaded guilty and were deported before the district court ruling.

Prosecutors had said they planned to charge more people before the ruling.