WASHINGTON : A convicted murderer became the final person to be executed in the United States this year, after being put to death Tuesday in Oklahoma, authorities said.

Johnny Dale Black, 48, was executed by lethal injection and pronounced dead at 6:08 pm (0008 GMT) at Oklahoma State Penitentiary, corrections department spokesman Jerry Massie said.

Massie said the condemned man’s final words were: “This isn’t accomplishing anything. It’s just another death, another family destroyed. I love everybody. I love you — you can count on that, Mama.”

Black’s death brings the total number of executions in 2013 to 39, the lowest figure since 37 inmates were put to death in 2008.  Black was sentenced to death in 1999 for the brutal murder of a horse trainer the previous year. He had already been convicted of another killing in 1984.

The Death Penalty Information Center (DPIC), which campaigns against capital punishment, said the number of executions for 2013 was likely to have dropped by around 10 percent from 2012.

Richard Dieter, director of the DPIC, said support for the death penalty in the United States was at a 40-year low, noting that 18 states were now without capital punishment after Maryland repealed the death penalty.

Since 1976, when capital punishment was reinstated in the United States, some 1,359 people have been executed, including 508 in Texas alone.

The numbers of executed have steadily declined since a spike in 1999, when 98 people were put to death.

The Death Penalty Information Center releases its annual report on Thursday.