Trial of Doctor Accused of Murdering Ex-Beauty Queen Wife Begins in Utah

Oct. 15, 2013— -- Jury selection begins today in the case of a Utah doctor who is accused of fatally drugging his former beauty queen wife so he could pursue an extramarital affair.

Martin MacNeill, 58, a once-prominent doctor and former Mormon Sunday school teacher, is accused of killing his wife in April 2007 after she approached him about his alleged affair.

Prosecutors allege MacNeill persuaded his wife, Michele MacNeill, 50, to have a facelift and then "intentionally overdosed" her with a lethal cocktail of Valium, Percocet and Ambien.

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MacNeill's cause of death was never determined and the medical examiner has never ruled it a homicide.

Two of MacNeill's daughters, Alexis Somers and Rachel MacNeill, have long-believed their father is guilty. They are expected to be star witnesses for the prosecution and have consistently been a presence in the court during pre-trial hearings, often clutching pictures of their mother as they glared at their father.

"He had a plan to murder my mother, and this was just part of his plan," Somers told ABC News in 2012.

While caring for her mother after the surgery, Somers said, her mother made an ominous statement.

"A few days before her death, I was helping her wash her hair and she turned to me and said, 'Alex, if anything happens to me, make sure it was not your father,'" Somers said.

On the day the mother of eight died, Martin MacNeill had arrived home after picking up Ada, the couple's then 6-year-old daughter from school.

The little girl then found her mother's lifeless body in the bathtub.

MacNeill has denied having anything to do with his wife's death.

The jury is also expected to hear from MacNeill's alleged mistress, Gypsy Willis, who moved into the family's home as a nanny weeks after Michele MacNeill's death.

MacNeill also served three years in a Texas federal prison for fraud and was released in July 2012.

His trial is scheduled to last six weeks and opening arguments are expected to begin Thursday.