When Island County Sheriff’s detectives Ed Wallace and Mark Birchfield took a trip to Marysville on April 11 to arrest a woman who had passed a number of stolen checks on South Whidbey, they were doing more than nabbing one of the bad guys. They were pulling the wraps off a problem that is becoming more prevalent with each passing week — identity theft.

The woman, whom Wallace identified as 45-year-old Norma Jean Trenowski, had gone far beyond writing bad checks. An investigation done by the sheriff’s office with help from the Langley Police Department show that Trenowski may be one of the top figures in a regional identity-theft ring that supplies false identification and stolen checks and credit cards to anyone willing to purchase them.

The South Whidbey incident, which took place between Feb. 20 and Feb. 21, victimized a number of businesses. Using a false state ID card, Trenowski allegedly wrote checks at several Langley businesses, including the Star Store. The checks, Wallace said, were stolen from the mailbox of a Snohomish County resident on an earlier date.

In all, Trenowski is accused of bilking South Whidbey businesses for about $1,000 in merchandise and cash. At most of the businesses she hit, Wallace said, she wrote checks for greater than the amount of her purchase.

Employees working at the stores on Trenowski’s route had little reason to suspect the woman. Kim Yang, who with her husband owns the Clinton Chevron station, said Trenowski came into her store with a local woman who has patronized the business in the past and with an ID card. Though the check she wrote was not approved by the store’s check verification machine, the employee decided the $180 in checks Trenowski wrote were probably good, since she had a local connection. Yang said her South Whidbey companion claimed that Trenowski was an aunt.

“As long is it is local people, we don’t worry too much,” she said Tuesday.

However, when she saw the checks, Yang knew they would not clear the bank. Her business generally does not accept out-of-area checks, especially those that are written for well over the amount of a purchase.

“This is very obvious,” she said.

Trenowski was arrested after Langley Police Officer Laura Price looked into stolen checks written at the Star Store. Using an image from the store’s security camera, she and sheriff’s detectives were able to identify her.

Later, at a regional meeting of sheriff’s detectives, Detective Wallace discovered that Island County law enforcement had a big fish on its hands. Snohomish County detectives identified Trenowski as being the number-three figure in a region-wide identity theft ring.

Wallace said what Trenowski and others like her are doing doesn’t hurt just business owners. By stealing someone’s checks and using them fraudulently, Wallace said a criminal can destroy another person’s credit history. This is not just stealing money — it is taking someone else’s identity. Wallace said identity theft can follow someone for years and can cause banks to turn down loan requests and credit card companies to reject applications even after law enforcement closes an ID theft case.

Langley Police Chief Bob Herzberg said merchants must now scrutinize customer IDs, checks and credit cards more carefully than ever. He said good fake IDs and stolen IDs are easy to come by, so asking only for a credit card as proof of identification when a customer writes a check doesn’t do the job anymore.

“To simply trust people at face value is to risk financial loss on a worthless piece of paper,” he said. “We need merchants who ask for ID.”

Wallace said merchants also need to break old habits to keep criminals guessing. South Whidbey, he said, is a targeted area, since trust still goes a long way on the island.

“The local network knows where to go and who won’t check,” he said.

Herzberg said his department gets several calls a week regarding credit fraud, bad checks and stolen financial information. Saying that information is easily stolen from mailboxes and off the Internet, Herzberg recommended that consumers be as wary as retailers. Having boxes of checks sent anywhere to a bank or a post office box is just a temptation for thieves.

Both Herzberg and Wallace recommend that merchants call law enforcement whenever they take a check or credit card they believe to be suspect.