Inmate Says Utah Doctor Called His Dead Wife a 'Bitch'

Inmate says Dr. Martin MacNeill told him there was no proof he killed his wife.

Nov. 5, 2013— -- An inmate who exercised with Dr. Martin MacNeill during the Utah doctor's stint in federal prison testified today at the doctor's murder trial that the physician called his dead wife "a bitch" and said no one could prove he killed her.

The man, who was identified as Inmate No. 3, told the court he met MacNeill when the physician served time at Texarkana Federal Prison for an unrelated identity fraud conviction. MacNeill was released from prison in July 2012.

Inmate No. 3 said the man other prisoners called "doc" would come to him with exercise questions.

"Sooner or later we started working out together," Inmate No. 3 said. He told the court he has served 14 of 27 years for a drug sentence and is not asking for any incentives in exchange for his testimony.

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The inmate, who appeared to be in his 30s, said he found a PEOPLE magazine article about MacNeill's wife in the prison library. It was torn up, he said, but he decided to ask his friend what happened.

"Doc" told him that, "if I did [kill her] they don't have any evidence," the inmate said.

He told the court that on another instance, MacNeill told him his deceased wife was "a bitch."

At least two other inmates were expected to testify today that the doctor boasted that no one could prove his wife was murdered.

MacNeill, 57, is on trial for the April 11, 2007, death of his wife, Michele MacNeill, 50. The former beauty queen's cause of death has been the main source of contention between the prosecution and defense.

Prosecutors allege MacNeill persuaded his wife to have plastic surgery so he could dope her up during her recovery and then drown her -- all so he could pursue a relationship with a mistress, Gypsy Willis.

MacNeill's defense lawyers said heart problems were a contributing factor in her death. The medical examiner was never able to rule on a cause of death, however Utah State Chief Medical Examiner Dr. Todd Grey testified last week that a drowning scenario was possible.

However, Grey told the court, "I did not feel I could reach a conclusion of homicide."

Doctor's Daughter Confronted Him About Over-Medicating Mom

In the days before Michele MacNeill was found unconscious in the bathtub, one of the couple's eldest daughters, Alexis Somers, confronted her dad about allegedly over-medicating her mom as she recovered from plastic surgery.

After Somers found her mother "very sedated" one day after she came home from the hospital on April 4, 2007, Somers, who was then a medical student, said she told her father, "I'm taking over."

Somers said her mother was a reluctant plastic surgery patient who didn't like taking all of the drugs her physician husband insisted she take during her recovery.

Watch the Full '20/20' Report: Life of Lies

After taking a cocktail of pills that left her sedated, Somers said her mother told her she no longer wanted MacNeill to dispense her medication since she couldn't see through the bandages on her face.

"She actually had me take out every single pill from the pill bottles and she wanted to feel what the pills feel like in her fingers, so if my dad tried to give her anything, she would know what he was giving her," Somers said.

On April 10, 2007, Somers said she left her family's home in Pleasant Grove, Utah, to go back to medical school in Henderson, Nev.

Somers told the court her mother "was feeling really well" when she left.

The next day, the mother of eight was found by her 6-year-old daughter unconscious in a bathtub full of brown water. Less than two hours later, Michele MacNeill was dead.

The trial, which is in its fourth of five scheduled weeks, has played out like a soap opera in the court room.

Willis, the woman who prosecutors allege was MacNeill's motive for murder, testified that she moved into the family's home days after Michele MacNeill's death and that she was hired to work as a nanny.

Four of MacNeill's daughters told the jury in Provo, Utah, that Willis never looked after the children, and instead was "goo eyes" at their father, who months later, proposed to her with a four-and-a-half carat diamond ring.