Oklahoma woman faces execution

Lethal injection is the most common form of execution

A woman is to be executed in the US state of Oklahoma on Tuesday despite concerns over the competence of a forensics laboratory worker who was involved in her murder conviction.

Marilyn Plantz, 40, was convicted of killing her husband Jim Plantz in 1988.

There was no question about her guilt - this lady admitted she did it

Governor Frank Keating

She is scheduled to die by lethal injection at the Oklahoma State Penitentiary in McAlester and will be the second woman executed in the state's history.

The human rights organisation Amnesty International, which opposes the death penalty, issued a report last week saying that Oklahoma's rate of executions was the highest in the US, and higher than that of China or Iran.

Insurance plot

Plantz was found guilty of plotting with two other men, including a lover, to murder her husband in order to collect on his $300,000 life insurance policy.

"There was no question about her guilt," said state Governor Frank Keating, refusing to block the execution. "This lady admitted she did it."

William Clifford Bryson and Clinton Eugene McKimble bludgeoned Mr Plantz to death with baseball bats while Mrs Plantz and her two children stayed in another room.

The men then placed Mr Plantz's body in his pickup truck on a rural road and burned it to make it look as if he had died in an accident.

Bryson was executed on 15 June.

McKimble was sentenced to life in prison in exchange for his testimony against Bryson and Plantz.

Laboratory dispute

A manager of the Oklahoma City police forensics laboratory involved in the case has been criticised for incompetence in an internal police memo.

Recent Federal Bureau of Investigation findings suggest that the lab worker, Joyce Gilchrist, may have made errors that led to innocent people being convicted.

The internal police document said that under Ms Gilchrist the serology laboratory was "grossly mismanaged", The Oklahoman newspaper reported.

Governor Keating said all felony cases on which she worked should be reviewed.

Her lawyer said Ms Gilchrist stands by her work.