AKRON, Ohio - A Youngstown convenience store operator, already serving a federal prison sentence, has pleaded guilty to charges filed in connection with $2 million food-stamp fraud plot carried out at his store.

George Rafidi, 62, appeared in U.S. District Court on Thursday, where he pleaded guilty to food stamp fraud and conspiracy to defraud food stamp programs.

A federal grand jury indicted Rafidi and 32 other people in March, alleging that from June 2010 to October 2014, the suspects took part in a conspiracy to defraud the Supplemental Nutrition Assistance Program (SNAP), formerly known as the Food Stamp Program by converting illegally obtained SNAP benefits into money.

Investigators say that SNAP beneficiaries went to Rafidi's Breaden Market in Youngstown where they obtained cash and prohibited items, such as alcohol and tobacco, in exchange for their SNAP benefits.

Over a period of more than four years, Rafidi redeemed more than $2 million in SNAP benefits, according to the indictment.

Most of the defendants were charged with using their SNAP Electronic Benefit Transfer cards in exchange for cash and other ineligible items.

Rafidi is already serving an eight year sentence for assaulting a federal officer in 2014. The officer was taking part in a search of Rafidi's Lordstown home as part of the food stamp investigation.

Rafidi will be sentenced for the food stamp convictions on January 4.