Clarence Ray Allen lived a double life

Lawyers for Allen, who turned 76 on Monday, said his age and condition, and the 23 years he spent on Death Row, were good reason to stop the execution. Appeal judges disagreed, and he was executed just after midnight on Tuesday.

Acquaintances say they do not know what turned Allen, at middle age, from a good friend and successful businessman into a cold-blooded criminal and murderer.

Allen, a father of two and a church deacon, was a warehouse manager and later the owner of a security business that employed 60 people.

Employees said he was a considerate boss; a sick friend said he was the first to offer a blood donation.

Manipulated accomplices

But always, alongside his legitimate lifestyle, he indulged in petty crime that grew in severity and violence.

A 'jovial' Allen received visitors hours before his execution

From stealing from the cars of fellow cotton-pickers when he was young, he graduated to robbing grocery stores and, in his 40s, fell in with a gang of misfits.

Investigators told how he scared and manipulated them, often using them to carry out his dirty work.

When Allen's gang robbed a grocery store in 1974, he became worried that his son's 17-year-old girlfriend, Mary Sue Kitts, would go to the police, and ordered an employee to kill her.

Hit list

In 1980, while serving a life sentence for that murder, he drew up a hit list of witnesses who had testified against him - and who he did not want to give evidence at his appeal - and paid a prisoner about to be released $25,000 to carry out his wishes.

The prisoner, Billy Ray Hamilton, tracked down witness Bryon Schletewitz at his grocery store, and also rounded up three of his colleagues. He shot them in turn. Three died but a fourth, who was shot in the face with a shotgun, survived and later gave evidence.

Death penalty opponents campaigned against the execution

In 1982 Allen was sentenced to death for ordering the murders.

After several appeals failed, and several scheduled execution dates passed, he suffered a heart attack in September.

He was revived and returned to Death Row.

Refusing to grant him clemency, California Governor Arnold Schwarzenegger said Allen's crimes reflected the "hardened and calculating decisions of a mature man".

"Allen's crimes are the most dangerous sort because they attack the justice system itself. The passage of time does not excuse Allen from the jury's punishment," he said.