A Florida couple pleaded guilty to bilking the federal government out of $257,000 in a food stamp fraud scheme at one of their convenience stores.

Russell Leroy Dotson, Jr., 62, and Maria Luisa Dotson, 65, both pleaded guilty to one count each of conspiracy to commit wire fraud for allegedly stealing $257,000 from the federal government over 27 months, WJXT reported.

If convicted, the pair could spend up to 20 years behind bars.

Prosecutors say that the Dotsons owned and ran two locations of the Asmarina Food Mart in Jacksonville, where they trained employees to give food stamp recipients cash back for half of what they redeemed while they pocketed the rest of the money made from the transaction.

The U.S. Attorney’s Office states that the Dotson’s case was part of a long-term investigation into Jacksonville area businesses for food stamp fraud.

It is unclear how much the couple will have to pay back the federal government, but 11 others have pleaded guilty to separate charges in their case. These 11 people have been ordered to pay the federal government back just over $218,000.

Food stamp fraud has become a vast criminal enterprise among convenience store owners who create these food stamp trafficking schemes as a way to make a quick buck. But it is also one of the ways the federal government can lose billions of dollars.

A Government Accountability Office (GAO) report from 2019 found that criminals were responsible for trafficking at least $1 billion in food stamp benefits, a steep cost to the taxpayer.

But federal agents have been able to recover some of the money through targeted raids and busts. Some of the biggest food stamp fraud busts of 2018 ranged in the tens of millions of dollars.