Workers are accused of cutting off the heads of cows with eye cancer and hiding them in bins of guts.
The heads of healthy cows were then placed near the bodies.
The Los Angeles Times reports employees and owners of the Rancho Feeding Corporation now face charges of conspiring to distribute adulterated, misbranded, and un-inspected meat.
An indictment obtained by the paper points to other horrifying details.
It alleges workers were told to chop out proof when beef had been "USDA Condemned," and prepare it to sell as normal.
The company was accused of shipping nearly 9 million pounds of “unsound" beef and veal earlier this year to vendors like Walmart, Kroger, and Nestle.
All of those products were later recalled.
"There are very few criminal prosecutions generally in food cases, and there are very few and far between in meat cases," attorney Bill Marler told KQED.
"They're facing some severe jail time and some severe fines."