Vincent Ashley was ordered by Circuit Judge O.H. Eaton Jr. to appear in court Tuesday to explain why he is changing his testimony. Ashley is currently in state prison, serving a life sentence in an unrelated armed robbery. He was given immunity in James Wright's slaying for his testimony against Mills.

Meanwhile, Mills' lawyer says the changes in Ashley's story lessen his credibility and should be grounds for the revocation of Mills' conviction and sentence.

Mills, 43, is scheduled to die May 2 for the shotgun slaying of Wright, a 73-year-old Sanford man who was killed in 1979 when he got up in the middle of the night to investigate the sound of burglars in his front room.

Mills was convicted of felony murder and sentenced to death. At the trial, Ashley testified that after Mills crawled into the house through a window, he did, too.

Ashley now says he never entered the house and that he stayed outside the window, said Todd Scher, Mills' attorney, who is asking Eaton to throw out Mills' conviction and sentence.

"To me, it just shows anything he has to say in this case is not credible," Scher said.

Assistant Attorney General Ken Nunnelley argued that even if Ashley has changed his story, the changes are insignificant and wouldn't have caused the jury to acquit him.

The jury that convicted Mills recommended a life sentence, knowing that Ashley got immunity in exchange for his testimony. But the trial judge sentenced Mills to death.

The state Supreme Court last week refused to stop Mills' execution.

In sharply worded dissent, three of the seven justices said the execution would be not only an injustice but also an arbitrary application of the death penalty.