Police say Jerrell Eubanks killed his William Park, by cramming the sandwich down his throat, choking him.
63-year-old Eubanks and 83-year-old Park were roommates at a nursing home in Magee, Mississippi.
WLBT reports cops are not sure why Eubanks, who was arrested last week, attacked Park.
Eubanks has been charged with second-degree murder while the Mississippi Attorney General's Medicaid Fraud Control Unit, and the Magee police department investigates the crime.
His bail has been set at $100,000.
More here.