LYNNWOOD — The fraudulent documents allegedly manufactured by four Mexican nationals are "intricate and sophisticated" and illustrate how adept criminals have become at making phony documents, investigators said Friday.

"In this day and age of computers and people’s ability to manipulate software, we’re vulnerable," said U.S. Immigration and Customs Enforcement Special Agent-in-Charge Leigh Winchell.

There is a new sense of urgency to these types of fraud cases following the Sept. 11, 2001, terrorist attacks, Winchell added.

Investigators seized hundreds of fake identification cards at two Burien apartments Monday. They found fake immigrant resident cards, Mexican consular cards, Social Security cards and driver’s licenses from around the country.

Computers, scanners, color copies and federal and state hologram seals also were discovered. Police also seized nearly a dozen cell phones, $6,000 in cash and a loaded pistol.

"It’s very significant. One, because of the large number of documents, and two, because of the quality of the documents," Winchell said.

The four King County men were arrested following a two-month joint investigation among federal agents and Lynnwood police. The investigation, dubbed Operation MICA, began when police nabbed an alleged drug dealer in Lynnwood.

The man had a fraudulent Mexican consular card, which he used to get a Washington state driver’s license, Lynnwood officer T.J. Brooks said.

Investigators were able to trace the fake card back to the four suspects, and over the course of two months undercover agents purchased 21 identification cards and driver’s licenses in King and Snohomish counties for $1,700, Winchell said.

Investigators are looking into whether any of the documents were used to set up fake bank accounts or allowed the suspects or buyers to steal anyone’s identity.

Winchell would not say if the suspects are tied to a larger group. They are not believed to be connected to six people arrested in Seattle and Los Angeles Thursday. Those people are accused of stealing the identities of more than 200 people and draining $750,000 from local banks.

Investigators are trying to learn more about how the suspects, ages 21 to 39, were able to re-create documents with such precision.

"We don’t know where they learned this," he said. "This was a unique operation. It was very compact and very mobile."

Two of the four men had been deported from California for similar charges. None of the men are legal U.S. residents.

The suspects told police they’d been running the document factory for about four months. They also admitted to running a similar setup in California for two years.

The men remain in the Snohomish County Jail. The case has been referred to the U.S. Attorney’s Office for possible federal charges. If convicted, the men could face up to 10 years in prison.

Reporter Diana Hefley: 425-339-3463 or hefley@heraldnet.com.