Mississippi executed its sixth death row inmate this year, overtaking Texas as the US state that has put the most inmates to death so far in 2012, authorities said.
Gary Carl Simmons (49) was put to death by lethal injection at 6:16pm (2316 GMT), prison officials said.
Simmons was a grocery store butcher who was convicted and sentenced to death in 1997 for dismembering a drug dealer to whom he owed money. He also was convicted of two life sentences for kidnapping and raping the woman who was with his victim.
Court documents show that Simmons and his accomplice, who was convicted in a separate trial, respectively owed $12 000 and $20 000 to the murder victim, Jeffery Wolfe.
Wolfe was attacked and cut up and his remains tossed into the bayou in August 1996 when he came from Texas to Pascagoula to collect money he was owed. His female companion was raped and locked up for hours in a metal foot locker. She was later released and went to police.
Simmons was the 22nd death row inmate to be executed in the United States this year, 17 of whom were in the southern United States.
With Simmons' execution, Mississippi now leads Texas in the number of death row inmates put to death this year.
"The executions that are occurring are from 10-15 years ago, or even longer. At various times, the quality of the defence attornies was not adequate, allowing for more death sentences, and consequently more executions," said Richard Dieter, who leads the Death Penalty Information Center.
"I believe that Mississippi executions will slow down in the years to come," he added. "Even in 2012, Texas will almost certainly finish the year with more executions than Mississippi."