That was the story Canadians had waited two years to hear. When the sensational trial of the alleged sex killer, a clean-cut young accountant named Paul Bernardo, finally began in Toronto last week, the prosecutor’s six-hour opening statement made listeners cringe. The ghastly details had been suppressed by a ban on pretrial publicity, although scraps of the story had circulated in Canada anyway. Now a jury has to decide whether the charges are true–and whether the leading villain is Bernardo, 30, or his pretty ex-wife, Karla Homolka, 25.

Nearly two years ago, after she left her husband, Homolka pleaded guilty to two counts of manslaughter and was sentenced to 12 years in prison. Prosecutor Ray Houlaban said Homolka would testify against Bernardo, and he described her as a victim herself, severely abused by her husband. Just before Christmas in 1990. Karla allegedly helped him ply her sister, Tammy, 15, with liquor and sleeping pills until she passed out. Bernardo is charged with raping Tammy and forcing Karla to perform oral sex on her, recording it all on video. The unconscious Tammy later died, choking on her own vomit in what was initially rifled an accidental death.

Bernardo’s current trial–two others may follow-concerns the kidnapping, rape and murder of Leslie Mahaffy, 14, in June 1991 and Kristen French, 15, in April 1992. Allegedly abducted from outside her house at night, Lesliewas strangled to death the next day with an electrical cord. (Homolka says she gave LeSlie a teddy bear for comfort when the girl begged for her life.) The prosecution says Bernardo cut her body into 10 pieces with a circular saw and encased them in cement blocks, later found in a lake.

The next April, the couple allegedly kidnapped Kristen French, forcing her into sexual servitude. But after two days, Kristen became defiant. Ordered to perform a particular sex act, she refused, insisting: “Some things are worth dying for.” She wouldn’t give in, even after Bernardo allegedly tried to intimidate her with videotape of Mahaffy’s final hours. Kristen was strangled in the master bedroom. Her corpse was buried intact.

Homolka had many opportunities to stop the killing, but her sister’s death gave Bernardo a hold over her, the prosecution said. “I could tell them what you did to Tammy, and your life would be over,” he was quoted as saying. Homolka was said to have broken away from Bernardo only when she concluded that she herself was destined to be his next murder victim.

Bernardo has been indicted for sexual assault and manslaughter in Tammy’s death and for more than a dozen unrelated sexual attacks in the Toronto suburb of Scarborough between 1987 and 1990. He has entered a plea of not guilty in the current Mahaffy-French trial. His lawyers contend that Homolka has shifted too much of the blame to him in order to obtain a light sentence. The incriminating videotapes may help appalled jurors decide where the truth lies.