By Alicia Dennis Ken Lee
November 18, 2013 12:00 PM

Shaking and trembling on the witness stand on Oct. 30, Vanessa MacNeill refused to make eye contact with her father, Martin, as she recounted how he said a nanny would allow the grieving MacNeill family to “get on with their lives” after her mother, Michele, had been found unresponsive in the bathtub. Though Vanessa offered to care for her younger siblings herself, her father insisted on the nanny, but only one woman showed up for an interview: Gypsy Willis. “I was convinced she wasn’t somebody that my dad might be involved with,” Vanessa, 32, said. She paused, took a deep breath—and then burst into tears. “Because she was nothing like my mom.”

Emotional outbursts, mistresses, daughters testifying against their own father before a packed courtroom: In the case of State of Utah vs. Martin MacNeill, the community of Provo is getting more than its fair share of highly charged drama. Martin MacNeill, 57, a father of eight and former physician, lawyer and Mormon Sunday-school teacher stands charged with first-degree murder in the April 11, 2007, death of his wife, Michele, 50. While MacNeill maintains his innocence—the defense states his wife died of a heart condition—prosecution witnesses’ testimony has revealed that he urged his wife to have a face-lift while he was having a 15-month-long affair with the woman he installed as nanny to his children, had at least one other mistress and had access to Michele’s medications. Her cause of death was changed from “natural” to “undetermined” in 2010 by Utah State Chief Medical Examiner Dr. Todd Grey, who admitted on the stand, “I did not feel I could reach a conclusion of homicide.” But along with MacNeill’s inconsistent accounts of her death—capped off by a vivid courtroom reenactment of the day she died, complete with a replica of the bathtub in which she was found—this series of deceptions makes up a damning pile of circumstantial evidence. “The mistresses, the fact his own daughters are against him, his lies,” says Joey Jackson, a criminal defense attorney not involved in the case, “all could help the jury look past the lack of scientific proof.”

The case has stripped away the facade of what had once appeared to be a perfect family. In the early years of their marriage, the dashing doctor and the former beauty queen and cheerleader, who spoke French, loved playing the violin and was a gifted interior decorator, seemed to be living the American dream. They shared an expansive home in the suburban gated community of Pleasant Grove, Utah, with their brood of eight children—three of them adopted from Ukraine. But after Michele died and the MacNeill daughters began investigating, dark secrets started to unfurl. MacNeill had been discharged from the military for alleged schizophrenia; he falsified his applications to get into medical and law school; he had a felony conviction for check fraud. “I wasn’t comfortable around him,” Linda Cluff, Michele’s sister, told PEOPLE prior to the trial. “He seemed like an actor putting on a play. He gave me the creeps.”

A parade of witnesses has so far confirmed these suspicions. Even MacNeill’s former mistress and nanny, Willis, 37, testified she’d attended his wife’s funeral. Willis’s mother, Vicki, told the court how MacNeill got down on one knee and proposed to her daughter three months after Michele died. The Willis family threw a fireworks celebration in their Cheyenne, Wyo., hometown in honor of the happy news. “He said to me that he had never loved Michele,” Vicki testified. “And then he amended that to say, ‘Well I did, I loved her as a sister but not the way I love Gypsy.'” Though the two never legally married, MacNeill listed a fictitious marriage date—April 14, 2007—on a military ID application he forged with Willis as they conspired to steal the identity of his oldest adopted child, Giselle. (MacNeill served three years in prison while Willis traded jail time for her testimony.) When asked on the stand about the significance of that date, Willis explained matter-of-factly that it was the date of Michele’s funeral. “I think that everyone agrees he is a sociopath and a horrible husband and father,” says Salt Lake City criminal defense attorney Greg Skordas, who is not involved in the case. “But whether that equates to murder, we don’t know yet.”

A second mistress, Anna Osborne Walthall, raised more questions. She revealed on the stand that while she was having a six-month affair with MacNeill that began in March 2005, he told her there was a way to induce a heart attack and make it look natural. “That was damning,” says attorney Jackson. “What normal person would talk about covering up a murder?”

More of MacNeill’s past may come back to haunt him: Five of his surviving seven children (son Damian committed suicide in 2010) have testified against him. The court heard a taped interview with his youngest daughter, Ada, from 2009 in which the then-7-year-old explained how she’d found her mother in the bathtub; when asked how she feels around her dad, she whispers, “I don’t want to talk about it.” Alexis, 30, now a physician, told the court about her mother’s fear that her father was over-medicating her; how her mother complained of throwing up throughout the night before she died. “Ever since the day my mother died,” she said, “I’ve been fighting to get justice for this case.” MacNeill’s son’s former girlfriend Eileen Heng, 27, revealed that MacNeill asked her to flush all of Michele’s remaining medication down the toilet, which she thought “strange.” Heng also testified she advised MacNeill against hiring Willis because it would cause family conflict. Heng said, “He said he didn’t want his kids controlling his life.”

As the trial continues into mid-November, MacNeill may discover that his children, who have fought for years to see their father convicted, won the battle for control after all. “When a man’s own daughters think their father is a murderer,” says former New York City homicide prosecutor Paul Callan, who is not involved in the case, “why wouldn’t the jury?”