Martin MacNeill and daughter Alexis Somers
11/11/2013 at 01:30 PM EST
Moments before the guilty verdict
was read against her father Martin MacNeill in a hushed Provo, Utah, courtroom just after 1 a.m. Saturday, his daughter Alexis Somers was already overcome with emotion.
"My whole body was trembling, I was so nervous and scared," says Somers, 31, who led a five-year crusade to get her father convicted of murdering her mother, Michele, 50. "My aunts and I were just clinging to each other. We had no idea how the verdicts would turn out."
As a court clerk announced the two guilty verdicts – for murder and obstruction of justice – Somers, her sister and aunts, cried out with relief as MacNeill, 57, stood at the defendant's table, stone-faced.
"It was a collective gasp," says Somers, whose chest heaved with emotion in the courtroom. "We'd been living in fear of our father for so long. He'd threatened to destroy us for standing up to him. To finally get justice for our mom was overwhelming."
MacNeill, who now faces life in prison at a Jan. 7 sentencing, was accused of overmedicating his wife of nearly 30 years and then drowning her in a bathtub to start a new life with his mistress
, Gypsy Willis, 37.
The case against MacNeill crystallized only after Somers, her sister Rachel, 34, and their aunt Linda Cluff, 53, uncovered his disturbing history of deception
: His multiple mistresses
, his past conviction of check fraud and a medical career based on falsified school transcripts.
"The person I knew as my father does not exist," Somers continues. "This is a person I once loved, and who I wanted to be proud of me. But we uncovered who our dad really is: a murderer. To now be responsible for him having to spend the rest of his life behind bars, it's overwhelming to think about. But he's an evil man who's capable of doing so much damage."
MacNeill faces a second trial next month for allegedly sexually assaulting Somers in the aftermath of his wife's death.
For now, Somers, herself a physician, says she'll focus on raising her three young children with her husband, as well as looking after her younger sisters.
"We now have a sense of relief and peace," Somers adds. "For the first time in six years, we can finally breathe. And now finally our mother can be at peace as well."