By Emily Le Coz

TUPELO, Mississippi (Reuters) - Mississippi executed a grocery store butcher on Wednesday who was found guilty of dismembering a man he owed for drugs with knives taken from work and then scattering the body parts in an alligator-infested bayou in 1996.

Gary Carl Simmons, 49, received a lethal injection at the Mississippi State Penitentiary in Parchman and was pronounced dead at 6:16 p.m., corrections spokesman Adam Lee said.

Simmons was the 22nd person executed in the United States this year and the third inmate put to death in Mississippi this month, according to the Death Penalty Information Center.

Mississippi now has executed six inmates in 2012, already the highest number carried out by the state in a single year since 1956, when there were eight executions.

Simmons was convicted of the August 1996 murder of 21-year-old Jeffery Wolfe. According to records from the Mississippi Supreme Court, Wolfe and his girlfriend drove from Houston to Mississippi to collect a drug debt of between $12,000 and $20,000.

But when they got to Simmons' house, Simmons and his accomplice, Timothy Milano, told Wolfe they did not have the drugs or the money, records showed. An argument erupted, and Milano fatally shot Wolfe with a .22-caliber rifle, records showed.

Simmons then hog-tied and locked Wolfe's girlfriend in a foot locker, removing her later to rape her and "telling her that her life depended on how well she performed sexually," the court document said.

Afterward, Simmons put the woman back inside the box and went into the bathroom, where he dismembered and gutted Wolfe's body in the bathtub using knives he had sharpened at work, the records showed.

Simmons and Milano scattered the victim's remains in a bayou behind Simmons' property, according to documents. Wolfe's girlfriend managed to escape from the foot locker and ran to a neighbor's house to call police, records showed.

Simmons was sentenced to death after being convicted in August 1997 of kidnapping, rape and capital murder. Milano was sentenced to life in prison.

Simmons requested a large final meal, which included pizza, parmesan cheese, ranch dressing, chips, jalapeno nacho cheese and peppers, strawberry milkshakes, cherry soda, french fries and strawberry ice cream.

Simmons "said he made peace with God and that he was remorseful," Mississippi Department of Corrections Commissioner Chris Epps said at a news conference ahead of the execution.

(Editing By Colleen Jenkins, Cynthia Johnston and Bill Trott)