Raleigh, N.C. — Experts warn that as the economy worsens, companies should be vigilant for an enemy from within: embezzlement.

Three months ago, Raleigh police told the owners of Quail Ridge Books & Music that their popular independent bookstore had been the victim of a seven-year-long embezzlement scheme by an employee.

Investigators say Anna Susan Kosak, of 5726 Osprey Cove Road, stole nearly $500,000 from Quail Ridge between November 2001 and September 2008.

"She was writing checks to herself and forging my name," bookstore owner Nancy Olson said. "As you could imagine, I was devastated."

Kosak's attorney, Kieran Shanahan, said she is out of jail on bond and working again. She is working with the government to resolve the case, Shanahan said.

Olson said she is hoping to recoup some of the money Kosak is accused of stealing.

Risk Management Associates investigates cases similar to that of Quail Ridge. Companies should look into suspected irregularities early and know the people they hire well, CEO William Booth said.

"Eighty percent of the companies in the United States do background investigations on their employees. And if you're not doing that, you're opening yourself up to these kinds of issues," Booth said.

Experts in the field of digital forensics – which analyzes evidence left in computers and digital storage devices – suggest that companies should install network monitoring software.

"It records everything they are doing. It records all the usage on the computer and allows management to go back and reconstruct that," said Leslie Denton, marketing manager at Guardian Digital Forensics.

Raleigh Police say embezzlement cases for the first quarter of the year were down 29 percent, contrasted to the same period of 2008.

Olson said she's learned the hard way and improved security measures at Quail Ridge.

"Bond your accountant, have theft insurance and have an outside audit – exactly what I would do," Olson said.