After a yearlong investigation into what police had described as a sophisticated stolen-goods fencing operation, the owners of a Lawrence store have been charged with drug usage and gun possession.

An indictment unsealed Tuesday from U.S. Attorney Eric Melgren’s office charges Guy S. Neighbors and his wife, Carrie Neighbors, the owners of Yellow House Store, 1904 Mass., with one count of possessing firearms while they “were unlawful users of a controlled substance.” Both were arrested Tuesday morning by agents from the Internal Revenue Service and the U.S. Postal Inspection Service.

The charge, which carries a penalty of up to 10 years in prison, is a relatively obscure one, according to Guy Neighbors’ attorney, Jim George.

“It’s one I haven’t seen before,” said George, who has been practicing criminal law in federal courts for 14 years.

The indictment claims the couple possessed four handguns, four rifles and three shotguns on or about Dec. 2, 2005, the day Lawrence Police served the first of a series of search warrants at the store and the Neighbors’ home in the 1100 block of Andover Street. Marijuana plants were found during one of the searches of their home.

A Lawrence Police Department spokesman said in December 2005 that the first search warrants served that month were part of a two-month investigation into “one of the largest, most sophisticated fencing operations” local police had seen, involving stolen goods sold in the Lawrence area and through the Internet.

Since then, the Neighbors have been vocal in their criticism of police, claiming they were unfairly singled out for the investigation. They claimed that Lawrence Police posed as FBI agents while interviewing witnesses – an allegation the FBI said was unfounded – and that during one of the searches of the store, legal interns for their previous attorney picketed in front of the shop carrying signs such as “Investigate police corruption.”

Guy Neighbors said earlier this month that he had filed a complaint against Lawrence Police alleging that officers had come to the store and started to question his wife without her attorney present.

Lawrence Police spokeswoman Kim Murphree on Tuesday referred questions about the case to the U.S. Attorney’s Office.

George, Guy Neighbors’ attorney, declined to give further comment about the case.