Thomas Maher argued that the jury that found Peterson guilty in 2003 was improperly allowed to hear evidence that should not have been admitted.

Peterson, now 63, was convicted in the death of his wife, Kathleen Peterson, 48. She was found dead Dec. 9, 2001, at the bottom of a staircase in the couple's Durham mansion.

Peterson, sentenced to life in prison and now being held at the Nash Correctional Institute, was not present for Monday's arguments. It is likely to be months before the court rules.

Maher, a Chapel Hill defense lawyer, argued Monday that prosecutors had failed to prove that the death of Kathleen Peterson, a Nortel executive, was a murder.

"She died accidentally in a fall," Maher said. "This is far from an overwhelming case for the state."

Appellate lawyers from the state Attorney General's Office argued otherwise.

"One cannot look at the pictures of the blood on the walls and the stairways of the Peterson home without common sense saying this was not an accident," said William Crumpler, an assistant attorney general.

A jury convicted Peterson of first-degree murder Oct. 10, 2003, after a two-month trial. Since then, Peterson has fought to have the verdict overturned.

Maher said Monday that evidence considered by the jury was "tainted."

Computer evidence that provided information about Peterson's homosexual interests, the couple's strained marriage and their financial difficulties was improperly acquired, he said.

But Crumpler and Jack Barnwell, state appellate lawyers, said prosecutors had used other evidence not on the computer to make the same arguments at trial.

Prosecutors maintain that the Petersons, with nearly $1.6 million in assets, were cash-poor, a situation that put a strain on their marriage and much pressure on Kathleen Peterson, whose salary was their source of income.

At the trial, prosecutors put forward the theory that Kathleen Peterson had found correspondence from her husband to a male prostitute and an argument ensued. She ended up at the base of a staircase in their home, bloodied.

Maher argued Monday that prosecutors should not have been allowed to introduce evidence about the death of a former Peterson neighbor in Germany -- a woman also found dead at the base of a staircase. The former neighbor, Elizabeth Ratliff, died in November 1985.

Prosecutors implied that Peterson was guilty of killing Ratliff -- although no such charges ever were filed against him.

Patricia Peterson, a former wife of Peterson's, lived in Germany with the novelist when Ratliff was found dead.

She was in the courtroom Monday to support her ex-husband.

During the hearing, justices asked numerous questions, many about cases cited in the appeal and others about the evidence.

Some of the questions involved evidence that came from sources other than the computer.

Divided panel

A panel of the state Court of Appeals last year upheld Peterson's conviction 2-1. Because the appeals panel was divided, the Supreme Court is reviewing the case.

Kathleen Peterson's daughter from a prior marriage, Caitlin Atwater, attended the hearing.

Peterson settled a wrongful death suit with Atwater, his stepdaughter, for $25 million. In the settlement, Atwater agreed to stay the case until Peterson's criminal appeals are exhausted. If he is ever exonerated, she would be allowed under the agreement to reinstate the suit. Peterson has filed for bankruptcy protection.

Peterson's sons and Ratliff's daughters, who were raised by Peterson and his former wife, also attended.

Todd Peterson, the younger son, had visited his father in prison over the weekend.

"We believe he's innocent," Todd Peterson said. "It breaks our heart seeing our father in prison."

But Atwater and Kathleen Peterson's sister have a different view.

"It's been six years, and it hasn't changed the fact that Michael murdered Kathleen," said Lori Campbell, her sister. "You all saw what he did to her."

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