UPDATE April 9, 2017: Utah doctor Martin Joseph MacNeill, serving a term of up to life in prison for drugging and drowning his wife so he could carry on an affair with another woman, was found dead in the Utah State Prison Sunday, KSTU-FOX 13 reports.

According to a press release from the Utah Department of Corrections, 60-year-old Martin Joseph MacNeill was found unresponsive in the outdoor yard of the Olympus Facility of the Utah State Prison Sunday morning.

While an investigation will determine the exact cause of death, the press release states there are no "obvious signs of foul play."

UPDATE March 17, 2017: The Utah Court of Appeals has upheld the murder conviction of a doctor accused of killing his wife so he could carry on an affair with another woman, KSTU-FOX 13 reports.

In a ruling issued Friday, March, 17, 2017, the state appeals court acknowledged that prosecutors should have disclosed a deal struck with a "jailhouse snitch" who testified against Dr. Martin MacNeill. However, the court said it was not enough to change the outcome of his high-profile murder trial.

“In sum, MacNeill has demonstrated no abuse of discretion by the trial court,” Judge Frederic Voros wrote in the opinion.

Oct. 31, 2016:

Martin MacNeill, a respected physician, calls 911 after finding his wife Michele clinging to life on April 11, 2007. The beauty queen and the doctor had been married for nearly 30 years and had eight children.

Emergency crews arrive on the scene, but they're unable to save Michele. Dr. MacNeill tells paramedics that his wife was recovering from plastic surgery, and that she must have overdosed on pain meds, hit her head in the bathtub and drowned.

But MacNeill's own daughters say their mother's tragic death was no accident. They claim their father killed Michele so he could carry on an affair with another woman.

With Michele out of the picture, MacNeill wasted no time moving Jillian "Gypsy" Willis into the family home as a nanny.

Prosecutors say that MacNeill was meticulous in carrying out his sinister plan, by pumping Michele full of the pain meds prescribed to her for plastic surgery. But the good doctor got a surprise from beyond the grave: His wife's ominous request.

Knowing he was having an affair, Michele's daughters say, she asked them to investigate her death if anything suspicious ever happened. It was a promise they kept, staying on top of detectives to pursue the case.

After several years, Martin MacNeill was arrested for murder.

According to the daughters, the new nanny did plenty of extra work -- after hours.

As part of a deal, Willis agreed to testify about her two-year affair with the doctor. On the witness stand, she read love letters from the doctor.

In court, prosecutors say just one day after Michele's death, Gypsy sent racy photos to MacNeill.

And after moving Gypsy into the family home, it wasn't long before MacNeill popped the question. According to testimony, despite not being officially married, Gypsy went by "Jillian MacNeill," wife of the defendant. On the stand, prosecutors showed her an I.D. card application Martin MacNeill filled out. There was a marriage date listed: April 14, 2007, the same day as Michele MacNeill's funeral.

In harrowing testimony, daughter Rachel MacNeill remembers finding gruesome evidence after her mother was killed.

On the witness stand, the medical examiner testified that Michele died of heart problems. Later he flip-flopped, saying Michelle MacNeill's death could have been a homicide. Ultimately, the medical examiner concluded that the cause of death was undetermined, and that homicide cannot be concluded.

In the end, Dr. MacNeill is convicted of murder and sentenced to 15 years to life in prison. But now MacNeill is asking the court of appeals to overturn his conviction, because prosecutors say testimony from a prison informant was tainted. The defense says an inmate witness who claimed MacNeill confessed to killing his wife had a deal with investigators that should have been disclosed.

But even with the request for a new trial, MacNeill's daughter Alexis Somers says she will do whatever it takes to make sure Martin MacNeill stays behind bars.