Last month in San Francisco, a trio of federal judges fired off an unusual legal opinion that landed 600 miles to the north, blasting the reputation of a Portland pediatrician who for more than a decade was a giant in Oregon's medical community.

On Oct. 16, ruling on a man's appeal of a child-rape conviction 15 years earlier, a three-judge panel said Dr. Jan Bays gave false testimony. Word of the opinion has rippled through Portland's law offices like a bad cold.

"This is an extraordinary opinion," says Stephen Houze, one of the better-known defense lawyers in town. "It is not just any witness who they said lied; it's the person who was held up as the guru in child sex abuse."

In 1987, Bays, a pediatrician, co-founded Legacy Emanuel's Child Abuse Response and Evaluation Services center. Over the next decade, before stepping down from her post as CARES medical director four years ago, child-abuse experts say Bays was a driving force in revolutionizing the field in Oregon and across the nation.

As the state's foremost expert on child sex abuse, she frequently testified in criminal trials as an expert witness. Former prosecutors and child advocates say that Bays has played an important role, both directly and indirectly, in jailing countless child molesters who would have otherwise gotten away scot-free.

But today, she is haunted by a case that happened in 1986 when Emanuel Sistrunk, a 39-year-old unemployed "meals on wheels" volunteer, was accused of raping an 11-year-old girl in a Laurelhurst resident's garage. Sistrunk was an acquaintance of her family, but there was neither physical evidence nor witnesses linking him to the crime--only the girl's testimony.

Bays took the stand as an expert witness who had examined the girl, whom the court dubbed Jane Roe. Bays related the findings of Roe's medical exam, which showed an abrasion and pain while urinating, consistent either with repeated touching or rape.

What later boomeranged on Bays, however, was her testimony that pre-teen children "never lie" about sex abuse. She said this was proven by a not-yet-published "scientific" study done by a clinic in Denver.

The jury unanimously declared Sistrunk guilty, and Judge Philip Abraham sentenced him to the toughest sentence possible: a minimum of 15 and a maximum 30 years in jail. "I only wish you could be incarcerated for the full 30 years," Abraham told Sistrunk, "because by that time your sexual desire would have burned out."

Sistrunk, who had maintained his innocence throughout, appealed his way through the state courts and finally into the federal arena. In his appeal to the San Francisco-based 9th Circuit Court, he argued that the study cited by Bays didn't say what she said it did.

Indeed, a copy of the study shows that, as opposed to conclusively determining whether kids' complaints were true, the study tallied up the proportion of complaints that social workers "considered" to be truthful or convincing. "This is subject to error," the authors cautioned. "All too often, we saw cases where it appeared that the professional mind had been made up well before sufficient information had been obtained."

In their opinion last month, a three-judge panel for the 9th Circuit agreed that the study "does not say what Dr. Bays testified it says, nor is it a scientific study establishing anything at all."

Despite the false representation, the two-judge majority found that Sistrunk would have been convicted with or without Bays. Her testimony was "disgraceful," they said, but it amounted to "icing on the cake" in the case against him.

While the two-judge majority did not think Bays' testimony was grounds for a new trial, the third judge dissented--using language that Portland lawyers describe as highly unusual.

"Emanuel Sistrunk has served almost 15 years for a crime he probably did not commit," wrote Judge Alex Kozinski. "We have here a gross miscarriage of justice."

Bays' defenders say she has impeccable integrity
and has always erred on the conservative side. So what happened?

In an interview, Bays, who is now semi-retired and leading a Zen Buddhist community in the Columbia Gorge, declined to go into detail about the Sistrunk case, saying she would respond in a soon-to-be-completed letter to the court. It is unclear whether Bays actually read a draft copy of the study--or just heard it summarized at a convention and misunderstood it.

As for her philosophy in diagnosing sex abuse, she says, "We try to be very conservative--we realize that the implications for the child and the suspect are very serious in these cases."

In any case, Sistrunk's attorney, Dennis Balske, has asked the 9th Circuit for another hearing, elaborating on Kozinski's reasoning.

Despite Kozinski's opinion, Sistrunk is unlikely to become a cause célèbre. In 1977, he was convicted of third-degree rape for having sex with a 16-year-old homeless girl in Eugene. In 1982, he was convicted of having sex with two mentally retarded patients at Marion County's Fairview Hospital, where he worked as an aide. In 1984, a mentally retarded woman living next door to Sistrunk in Portland told police he raped her twice (she declined to press charges).

And whatever the outcome of his appeal, Sistrunk won't get out of prison anytime soon. Since the Roe case, he has racked up two more felonies behind bars: possession of a weapon and assaulting another inmate. So even if he gets another trial on the Roe case, it is unlikely to spare him from serving nine more years.

Though Sistrunk may not be the right example, most defense lawyers say the ruling points to a larger problem: that in child sex-abuse cases people can be more easily convicted wrongfully, on even the flimsiest of cases.

In part, they say, it's because of a notion that "children don't lie" that persists among some advocates to this day.

Says Houze, "It makes you wonder how many people are in prison based on testimony like that."