Although courts have allowed repressed memories, several convictions in high-profile cases have been overturned based on repressed- and recovered-memory testimony. In 1995, for instance, a federal judge overturned the 1990 conviction of George Franklin Jr.
Franklin's daughter accused him of the 1969 murder of her 8-year-old best friend 20 years after the murder, saying she had recovered a memory of her father holding a rock over her friend's head. The judge overturned the verdict after Franklin's daughter accused him of a second murder.
Yet Murphy asserts repressed memories, in the form of dissociative amnesia, are considered a valid phenomenon by psychiatrists across several countries.
"The way that you know for certain that it is not a scientific dispute, is if you look at the DSM -- that's essentially the bible for psychiatrists," Murphy said of the Diagnostic and Statistical Manual of Mental Disorders.
Indeed, "dissociative amnesia" was an entry in the extensively peer-reviewed and researched DSM, which serves as the equivalent of the Physician's Desk Reference for those in the mental health field.
"Who are we as the judicial branch to say otherwise that it's not accepted in psychiatry," Murphy said.
Intentionally or not, legal experts say Shanley's appeal also challenges a 1993 Supreme Court decision, Daubert v. Merrell Dow Pharmaceuticals, that set a standard that judges -- not an academic or scientific community -- should decide which expert testimony is acceptable for the court.
"It's where the judge gets to serve as gatekeeper," said Rosanna Cavallaro, a professor who teaches evidence at Suffolk University Law School in Boston. "The question for the judge is whether the methods and techniques provided by the expert are legitimate."
With the exception of banning lie-detector results as evidence in many courts, Cavallaro said most appellate courts now leave the discretion of which expert is credentialed enough for testimony to the individual judge.
"What the court was worried about was that there would be this time lag," Cavallaro said. "For example, what if I'm the first scientist to say this drug can treat cancer, but the general acceptance among doctors wouldn't agree for five to 10 years."
But unlike in the case of cancer, Cavallaro pointed out, psychiatrists can't set up controlled abuse experiments to test a theory. Usually, psychiatrists can only survey and ask abuse victims after the crime.
Complicating the issue further are the prominent clinical psychiatrists who report treating repressed memories first hand -- even if it's rare.
"It really raises the whole question, what's the difference between forgetting and repression -- which is not the same as forgetting," said Dr. Philip R Muskin, a professor of clinical psychiatry at Columbia University in New York City.
"I've certainly seen patients who said, 'I was in an accident and we were driving down the road' and the next thing they know is they're in a neck brace -- and I have seen patients who have been assaulted who say, 'I can't remember the details of what happened but I know it happened'," Muskin said.
Yet while Muskin said he has seen patients who have blocked out moments in a traumatic memory, he has not yet heard of someone repressing the memory of the entire event.