When the police found them in an abandoned building in Oakland, the identical twin girls were almost 5 years old, malnourished, filthy and lice-ridden. They had never learned to talk and had survived by eating berries from bushes in weed-covered lots or begging morsels from the corner grocery. Both parents were reportedly drug addicts who left the girls and their seven siblings alone for days at a time. Child welfare authorities took all nine children into custody, and though their brothers and sisters were scattered among foster homes, the twins, Rachel and Toni, were kept together.

The two girls' memories of the orphanage where they spent the next several months are sketchy and unpleasant. They recall being struck with thick rulers, having their heads shaved to combat lice, feeling overcome by loneliness. When foster parents with two daughters of their own agreed, reluctantly, to take them in, the neglect of the twins' first five years was followed by abuse for the next two. They remember being beaten by their foster mother with "a big, huge belt with a buckle on it." A social worker concluded that the foster mother was "easily overwhelmed" by the added responsibility, and recommended that the twins be placed for adoption.

In 1973, just before the girls' 7th birthday, Dr. Joseph Royce, a tenured professor of kinesiology—the study of body mechanics—at the University of California at Berkeley, suddenly appeared in their lives as a savior. Royce and his wife, Doreliesje, were a social worker's dream: a well-respected academic and a career housewife who had devoted herself to raising the couple's three children. They had a spacious home in an affluent Berkeley neighborhood. They had an ample income and glowing references. A 20-year colleague wrote of the deep affection his eight children had for the Royces. "If you set out to find an ideal, tranquil haven for a youngster, you could do no better," he declared.

Appearances, in this case, turned out to be devastatingly deceiving. Friends, colleagues and authorities would not learn for another 11 years that Royce was apparently interested in the girls for sexual exploitation. Not until they were 18 would the twins find the courage to disclose that they and, according to police reports, at least eight other children had been his victims. Now, as their story unfolds in a California courtroom this week in a precedent-setting $20 million civil suit against Royce, the sordid but instructive tale of how he managed to harm so many children without being caught will finally be told. Though few in Berkeley were at first willing to credit such charges against a respected member of their community—who is now serving a 10-year sentence for a variety of sexual offenses—the twins have persevered, determined that Royce, 65, be punished. "People need a reminder that this can happen to anyone's child," says Rachel. "You can't be fooled anymore. The most important thing to do to prevent sexual abuse is to be aware."

Both Joseph Royce, known as Joop (rhymes with rope), and Doreliesje, nicknamed Do (rhymes with go), were born in Holland. Royce was raised in Indonesia and as a teenager was imprisoned with his family in concentration camps, first by the Japanese during World War II and later, along with other Dutch citizens, by Indonesian nationalists. After his release, he returned to Holland to complete his education and married Do, then 21, in 1948. They emigrated to Toronto in 1951 and to the United States a year later. Royce earned a Ph.D. in physical education at the University of Illinois and fathered two sons before accepting a professorship at Berkeley in 1956. After a third son was born in 1964, the Royces adopted an infant girl, Inge, "because we kept having boys," Do said later. From 1966 to 1968, the family lived in Micronesia while Royce served as a project director in the Peace Corps. When Inge was 7, she developed a brain tumor and died a lingering death, with both parents caring for her around the clock. Within a year, the Royces once again applied to adopt a girl. Soon afterward, the twins became available for placement.

Rachel and Toni were taken to visit the Royces and were suitably impressed by the huge trampoline in the backyard and the roomful of toys that awaited them. "It was exciting at first, but a little scary," Toni remembers. "We'd never been touched in an affectionate way, and we were so freaked out when they would try to hug us and kiss us goodnight. We'd cower away." Gradually the girls began to accept these overtures of affection, leading the social worker to believe the placement was an unqualified success.

Not long after the twins were welcomed into the household, Royce befriended another little girl, Harriet Brown (a pseudonym), whose parents were divorced. Her father, an alcoholic and a friend of Royce's, had custody and seemed relieved when Joop began to bring the girl, then 11, into the Royce family. Harriet recalls that she was immediately drawn to Royce simply because "he was paying attention to me." Royce encouraged her attempts at poetry and included her on trips to the family cabin in Sonoma County. He became her confidant, as he had for a number of other young girls from unhappy homes. "He has an unusual gift of understanding children," wrote a neighbor in 1973, recommending Joop as an adoptive father.

After the twins entered grade school, other little girls were drawn into the Royce circle. Friends of Rachel and Toni loved to visit the big, four-story house with the trampoline and hot tub in the backyard and the nice father who listened to all their problems. "He just seemed like a cool dad. Everything you got to do was fun," recalls a schoolmate. Parents were equally impressed. "Joop had this wonderful, charismatic way about him and seemed real concerned about the kids," said Dr. Lisa Jackson (also a pseudonym), a Berkeley physician whose daughter was often a guest of the Royces. "He was a very sexy man, I mean he'd knock you out. He was from Indonesia, and he'd be wrapped in a sarong when I'd go over there. He was so nice-looking and attractive."

Royce's generosity was renowned. He took Harriet on a trip to Europe when she was 12 and included her on several trips to Micronesia and the Far East with the twins. When he visited Peace Corps friends in Micronesia in 1979, he grandly offered to educate two of their young daughters, who were cousins, in Berkeley, and their families gratefully accepted. Thus were added Jonie and Virginia, then 10 and 12, to the Royce household.

There was increasing tension, however, between Royce and Do, who was often left at home while Joop traveled. She admits that she initially opposed adopting the twins, but says she later decided her husband's interest in young girls was his way of compensating for Inge's death. Gradually, though, she came to blame all the girls around the house for the increasing distance between herself and her husband. After 29 years of marriage, Do fell in love with a family friend, a neurophysiology professor named Walter Freeman. In 1977 she moved out to live with and eventually marry him, leaving three young girls in Royce's custody. (By this time, Harriet lived full-time with Royce.)

Do's affair was a campus scandal. Sympathy was heaped on Royce, struggling alone to care for the girls. (His sons, by this time, were on their own.) But Royce's shining image as father figure, according to the criminal investigation, concealed the insidious truth—that the professor was leading a secret double life of sexual perversion and domestic violence. Onlookers were unaware of the physical and emotional battering that Do had suffered in silence but would later reveal in depositions. Nor did they know of the unmitigated misery the twins were forced to endure. Virtually from the day of their arrival in the Royce home, the twins testified, their adoptive father beat them often and sexually assaulted them almost daily. He fanatically policed their diets so that their bodies would remain childlike, even in adolescence. Once, the twins recall, when he discovered that they'd made themselves pancakes—a forbidden fattening food—Royce dragged the girls into the kitchen by their hair and thrashed them.

The twins and other children have also told police that Royce took hundreds of pornographic photos of his charges, forcing them to engage in sexual acts with himself, male students and other children. Rachel, Toni and Harriet also testified they often had to accompany Royce to the university photo lab, where he would develop his film and become so aroused in the process that he assaulted them there or in his office.

The girls testified that the abuse began every morning at 6; Royce would rise an hour before Do awakened and slip into the twins' beds for fondling. "The thing I remember most is feeling disgusting and seeing him and not wanting to do it," says Rachel. "He showed us magazines of little girls having sex with dirty old men and animals," says Toni. "I guess to show us that it happened, so we would think it was okay, normal."

On trips to the cabin, Harriet recalls, Royce made all five girls sleep naked on the same platform bed with him. When one such incident led to an assault, says Harriet, "I was just emotionally and physically paralyzed. I remember going home that weekend feeling so conflicted, just sitting on my bed sobbing and not knowing why I was crying. I was 11 years old, and I had no way to understand what was going on. It was a feeling of death." As he had with the others, Royce warned Harriet not to tell, or she would go to jail. "He also trained me extensively if the police would question me. He told me he would never, ever admit to this, and if the police came to me and said he did, that I would know it was a lie," she recalls.

Royce's monstrous regime of deceit and treachery began to crumble in January 1981, when the twins, who were then 15, confided in a cousin who was visiting during the Christmas holidays. The girl told her father, Royce's brother, Theo Rus. Theo and Do (who later said that she had never been aware of Royce's abuse of the twins though she had suspected it with Harriet) began questioning Rachel and Toni, and tearfully the two told their story. Theo took the twins back to his home in Seattle, then confronted Royce, who vehemently denied their accusations. Harriet, who remained with Royce because she had no place else to go, vividly remembers Joop's panic as he burned all the pornographic photos he'd taken over the years. "He'd told me he was a pioneer in the sexual world and that in 20 years everybody would be taking on a young girl or boy and teaching them the joys of sex," Harriet says. "He said that people just didn't understand."

Do would later admit to the twins' attorneys that she cut a deal with Royce: She agreed not to prosecute him for sexual abuse if he would grant her custody of the twins. When a Seattle therapist who was treating the girls alerted the Berkeley police, Do warned the twins not to cooperate and terminated their therapy. "A man's life and career are involved here," the therapist says Do told her. Thus shielded, Royce was able to continue his double life for three more years. The twins returned to Berkeley to live with Do and without therapy slid into a self-destructive spiral that included shooting drugs, shaving their heads, running away and attempting suicide several times.

Harriet, now 26 and a counselor for emotionally disturbed teenagers, burns with anger at Do's willingness to turn a blind eye. "What's really hurtful is that the person who needs protection in that situation is the kid, the little one who can't protect herself," says Harriet. "But people are so concerned about creating a mess or ruining a person's reputation that they'll protect the perpetrator. The message that gave me was that I wasn't precious enough for somebody to step in and do something. That he was more important than I was."

The conspiracy of silence was finally broken by the twins themselves, shortly before they turned 18. Inspired by a newspaper account of another girl who had sued her father for sexual abuse, they found two women lawyers to file a similar suit against Royce in 1984. "We weren't really thinking of recovering money," says Toni. "We just wanted to let everyone know what a jerk this guy is and put him in jail." Their disclosures were met with stunned disbelief around the Berkeley campus, where Royce had taught for 28 years. Colleagues cited Royce's popularity among students and his educational research as "proof that he was not a pedophile. "He's definitely a scholar, and I presume he's a responsible person," said one instructor in Royce's defense.

Royce denied the twins' charges, telling well-wishers that the girls were deluded and greedy. Neighbors and friends rallied to his aid, offering to testify as character witnesses—until some of their own children began to disclose that they too had been abused. "I wanted to murder him," says Lisa Jackson, whose daughter was among Royce's victims. "How could I have been so stupid?" Suddenly the sex crimes unit of the tiny Berkeley Police Department had more complaints against Royce than it could properly investigate. As police pieced together the evidence, it became apparent that Royce had betrayed the trust of his most intimate friends by preying upon their children, one of whom was his own godson. Police now believe that over 12 years he assaulted at least 10 children.

Although criminal charges were filed, many of the complaints could not be prosecuted because the six-year statute of limitations on sex crimes had already expired in some cases. Armed with a warrant, police searched the Royce home in the fall of 1984 and found 13-year-old Jonie, whom he had spirited back from Micronesia in 1980. Police also discovered a box of child-pornography magazines Royce had failed to burn and a new wife, a young Micronesian woman named Juwariah, and her son, Tahal, whom Royce claims to have fathered, though he admits he had a vasectomy years ago.

Ultimately, Royce was charged with 36 felony counts of lewd and lascivious behavior and oral copulation. On July 22, 1986, to avoid a trial and a possible 80-year sentence on all counts, he pleaded "no contest" to 21 counts involving only three girls in exchange for a 10-year sentence. Royce, who will be eligible for parole in January 1992, told the judge his concentration camp imprisonment should be a mitigating factor. The judge replied that his own father had been a prisoner of the Japanese but had gone on to lead an honorable life without sexually abusing children.

Meanwhile, Rachel and Toni, now 23, have struggled to find some measure of emotional stability. Rachel married in 1984 and has a son, Raymond, 5, but has separated from her husband. She attends college sporadically, hoping to earn an M.B.A. and start her own business. "The abuse affects me to this day," she says. "I go into deep depressions, close all the curtains, drop Raymond off at school and just sit for hours and do nothing. I get paralyzed." Toni has moved to Seattle, where she is a biochemistry major and works in a laboratory. "I'm still lost," she says. "I'm still confused and completely depressed and anxious about him getting out of prison."

This week their civil suit, filed nearly five years ago, finally comes to trial in Alameda County Court in Oakland. Despite his failure to contest the criminal charges against him, Royce steadfastly denies having sexual relations with any child. He denounces his accusers as "bitches, snakes," and accuses them of ingratitude for all that he gave them. "I never had sexual intercourse with these girls, never in my life," he told the attorneys deposing him. "Let's get that straight. I didn't do that. I'm not the type."