The reports, prepared by Dr. John Penistan, would have been formidable weapons in the hands of Truscott's defence lawyer, Frank Donnelly, who could have used them to challenge the pathologist's claim that Lynne died at a time when Truscott had exclusive opportunity to kill her, Philip Campbell, one of Truscott's lawyers, argued Tuesday.

"It could have had a powerful effect on the jury," Campbell told a five-judge panel reviewing the case.

Campbell said it's impossible to underestimate the significance of Penistan's trial testimony that 12-year-old Lynne was dead by 7.45 p.m. on June 9, 1959 - a conclusion that had "the capacity to dictate the verdict."

Penistan's opinion was based on his examination of Lynne's stomach contents during an autopsy and the time of her last meal - 5.45 p.m. on June 9, 1959.

He told the jury the stomach normally empties within two hours of eating and Lynne's stomach appeared to contain a full meal.

Relying on these factors, Penistan provided jurors with his view that Lynne had died between 7 p.m. and 7.45 p.m. on June 9, 1959 - a time when Truscott, then 14, was admittedly in her company.

"If Lynne was dead by 7.45 p.m., it is an ineluctable matter of logic that the appellant killed her," Campbell told the court.

But since 1959, science has come to view the tidy notion of fixing a person's time of death based on what was in their stomach as an untenable proposition, he said.

Research conducted since the 1960s has also shown that a person's stomach can normally take up to six hours to empty.

Like the debate over whether smoking causes cancer or humans are a source of climate change, the controversy about what can be discerned from Lynne's stomach contents has been resolved - in Truscott's favour, said Campbell.

Nearly 48 years ago, Penistan's autopsy reports had the potential to do the same, he suggested.

Penistan's handwritten notes from the autopsy, prepared before police had identified Truscott as a suspect, place Lynne's time of death at approximately 12.45 a.m. on June 10, 1959, some 40 hours before her body was identified. A second report estimates she died about an hour before sunrise on June 10.

Penistan's autopsy notes surfaced during a federal investigation of the case by retired Quebec appellate judge Fred Kaufman from 2001-2004 and the second report was found in Stratford hospital archives in 2005.

In the documents, Penistan's descriptions of the food found in Lynne's stomach seem to become more detailed over time, as police learn more from Lynne's parents about what she had for dinner the night she disappeared.

In his earliest writings, Penistan notes there was "no obvious meat" in the jar of undigested food he held up to a light for examination. His later reports refer to the presence of meat, including turkey and possibly ham. The Harpers, meanwhile, had reported that Lynne had turkey for supper and access to ham and bologna in their fridge.

With the reports suggesting a possible propensity on the part of the doctor to tailor evidence to fit the prosecution's case, Campbell said a defence lawyer could have made hay of those findings. "There are things in here for a lawyer to savour," he told the court.

In 1966, before the case reached the Supreme Court, Penistan prepared what he described as an "agonizing reappraisal" of his 1959 testimony. In his reassessment, he concluded Lynne could have died up to 12 hours after her last meal.

Truscott's lawyer at the 1966 hearing, G. Arthur Martin, almost certainly did not have access to Penistan's reappraisal, which arguably amounted to a recantation, Campbell said.

If he had, Martin surely would have used the report or even called Penistan as a witness, he argued.

Truscott was 14 years old when he was sentenced to hang for Harper's death - a sentence that was later commuted to life in prison. He was paroled after 10 years in jail.

The hearing continues.