Utah doctor on trial for allegedly killing his wife 

A doctor accused of murdering his wife, whose own daughters are set to testify against him, is on trial in Utah in what is the state's first televised criminal case.

Dr. Martin MacNeill, 57, was portrayed as a cold-blooded killer by the prosecution on Thursday, a man who told fellow inmates he could get away with murder while serving time on a separate conviction. Prosecutors, who have been building their case for six years, allege he poisoned his wife, Michele MacNeill, 50, to continue an affair with his mistress. He is being accused of providing his wife with a deadly amount of prescription pills following plastic surgery in April of 2007 and then drowning her in the bathtub.

Eight days after her surgery, Michele MacNeill was found dead in her bathtub by daughter Ada, who was six at the time and is the youngest daughter out of the couple’s eight children. The surgeon who performed the facelift on Michele MacNeill testified Thursday that there were no complications involved in the surgery, suggesting she would not have been in an abnormal amount of pain requiring extra medication.

"(Proving) causation is going to be a problem, showing that not only did he overmedicate her, but he did so intentionally," NBC News legal analyst Lisa Bloom told Matt Lauer on TODAY Friday.

MacNeill has pled not guilty. His lawyers say that he was at work at the Utah Developmental Center when her death occurred. 

"If you kill somebody by giving them a lot of pills, they don't necessarily die instantly, it's not like a gunshot,'' Bloom said. "I think the prosecution can find enough time in the timeline to show he's good for this crime." 

MacNeill's defense team also noted that in the coroner’s report, none of the medical examiners believe that his wife’s death was due to a homicide. His attorney Susanne Gustin argued that medical experts agree that Michele MacNeill's heart disease was a contributing cause of her death, there was no evidence of a struggle prior to her death, and that the drug levels in her system were not exceedingly high.

Her death was never ruled a homicide, but one of the MacNeills' daughters, Alexis Somers, has long accused her father of murder. She and her sisters have been in court, holding up pictures of her mother, and are poised to testify against their father in a trial expected to take about five weeks.

“He killed my mother, who was my best friend, this amazing woman, this incredible person,” Somers told TODAY, in an interview that aired Friday.

Prosecutors say his motive for the murder was the woman they allege was his mistress, Gypsy Willis, who moved into the family home after Michele MacNeill’s death and even attended her funeral. The prosecution claims MacNeill and Willis exchanged over 20 text messages on the day of the funeral, and that after the funeral MacNeill was “jovial, laughing and smiling.” 

"He's not accused of being an adulterer, he's accused of being a murderer, but boy that fact doesn't help him,'' Bloom said. "It sure gives him a motive." 

MacNeill and Willis have both been convicted of fraud-related charges in a separate case that occurred after his wife was found dead. He spent four years in a federal prison in Texas, where prosecutors allege he told fellow inmates that law enforcement could not prove his wife's death was murder and that "he can get away with things." 

If MacNeill is found guilty, he faces life in prison.