In 2008, federal investigators shut down a temporary staffing agency and its high-profile owner, Doris Ruiz. Affidavits filed in federal court alleged that she placed illegal immigrants with regional businesses, provided false documentation and did not pay taxes for herself or workers for several years.

Two years earlier, a Carlton County sheriff's deputy stopped Ruiz in a car with several undocumented workers on their way to a job site. An assistant county attorney said he was told to dismiss a complaint to make way for federal charges -- charges that were never filed.

Now, Ruiz appears to be back in business, and that business also is employing illegal immigrants, a worker at the job site said last week. The hiring of illegal immigrants has become a hot-button issue locally as the Obama administration cracks down nationally on employers using undocumented workers. At least 2,000 people in the Twin Cities have lost their jobs in the past 18 months as a result of U.S. Immigration and Customs Enforcement (ICE) finding that they couldn't prove their eligibility to work in the United States.

So what happened to the Ruiz investigation and why has no one been charged?

The feds aren't talking. But the investigation into Ruiz and her fiance, Ralph David Rivera, apparently is alive, even though it's been nearly five years since Ruiz' first encounter with law enforcement. Jeanne Cooney, a spokeswoman for the U.S. attorney's office here, said: "We can't comment on an ongoing investigation."

Eric Olson, an attorney who said he represents Ruiz, would not comment on the investigation or the allegations. Rivera and Ruiz did talk last week, each denying they have done anything wrong.

"I haven't done that in the past, why would I do that now?" Ruiz said after being asked if the new business, Rivera Exteriors, hired illegal workers.

Said Rivera: "They are all certified. They have all been documented."

Federal investigation

Three years ago, Ruiz was a well-publicized champion of putting immigrants in hard-to-fill jobs.

Her Minneapolis-based company, Olen Staff Co., placed hundreds of mostly Mexican-born workers with employers across the region. She served on Minneapolis Mayor R.T. Rybak's Latino Advisory Committee. She and Rivera opened a restaurant in Minneapolis called Lucuma. The Star Tribune even featured Ruiz in a May 2005 story highlighting her company's work. Business was good.

But, tipped off by an anonymous informant in January 2006, federal agents began digging into the agency headed by Ruiz and Rivera. What they found, according to an affidavit, was that Olen Staff "primarily employed persons who have illegally entered or are illegally present in the United States. These persons are placed by Olen Staff Co. in work assignments with other companies."

The affidavit stated that Ruiz and Rivera "have facilitated, concealed and derived substantial income from this employment of illegal aliens."

The Social Security Administration found that in 2003 and 2004, more than 85 percent of the Social Security numbers were fake. After Olen Staff was informed about the false numbers, the company simply stopped filing tax returns. But there was more.

In May 2006, a sheriff's deputy in Carlton County pulled over a Mercedes-Benz going north on Interstate 35 near Scanlon, Minn., for excessive window tinting. Sheriff's records detail that Ruiz, three other adults and two small children were in the car.

Ruiz said she was taking employees to a work assignment in Ashland, Wis. But, according to the U.S. Border Patrol, the workers were in the country illegally. The workers told agents that when they told Ruiz they did not have identification documents, "Doris told them that was OK," the affidavit stated.

During a July 2006 undercover operation, a confidential informant posing as a job-seeker met with Ruiz and told her he had no legal documentation. According to the affidavit, Rivera drove the man to Ashland and left him in an apartment there.

James Ross, an assistant Carlton County attorney, said he had state labor trafficking charges prepared against Ruiz. Then he was contacted by an agent with the U.S. Treasury Department.

"They can't go forward unless we dismiss our action," Ross recalled the agent telling him. "I said, 'Fine, that's fine with me.'"

Back in business?

Following the 2008 search of Ruiz and Rivera's home, Olen Staff and Ruiz disappeared from public view. The restaurant closed about the same time. But nothing new has been filed in connection with the investigation. No new affidavits -- and no charges.

Yet, according to another informant working with ICE, Ruiz and Rivera are operating a new business under the name Rivera Exteriors. They use subcontractors instead of employees, the informant said. But they continue using illegal immigrants.

Over the past few weeks, workers have been replacing the slate tile roof at Avenues for Homeless Youth in north Minneapolis. Deb Loon, executive director of Avenues, confirmed hiring Rivera Exteriors. A white van, registered to Ruiz, has been at the job site several times.

Last week, one of the workers came down from the roof to talk. The man said the roofers are employed by a couple of subcontractors hired by Ruiz. They had been working at the site about 20 days, he said.

All of them are "no son bañados," he said. The literal meaning: They are not bathed. What that means, he said, is that they are undocumented.

Rivera, reached last week, said his workers are legal. When told what the roofer said, he said, "Why don't you catch the real criminals? Are you the police?"

Said Ruiz: "I am just a regular Joe.''

James Walsh • 612-673-7428