Dr. Martin mcneill was a prominent utah physician with eight children who loved and looked up to him. After his former beauty queen wife suddenly died in their home it was their eldest daughters who... See More
Dr. Martin mcneill was a prominent utah physician with eight children who loved and looked up to him. After his former beauty queen wife suddenly died in their home it was their eldest daughters who pressed the authorities for many years to charge their own father. Tonight on trial for murder, his bizarre case went to a jury who will now decide his fate. It is our series "crime & punishment". Did you give michelle the drugs, fix her up a bath, get her in the tub, hold her head down for a little while, and help her out. Reporter: That's how prosecutors say 57-year-old martin mcneill murdered his wife in the bathtub of their suburban home. Her death was not the result of an accident. And it was most certainly not the result of a heart condition. The defendant carried out a cold and calculated plan to murder his wife. Reporter: The star witnesses, mcneill's own daughters who were single-handedly responsible for convincing prosecutors to bring charges against their father. Ever since the day my mom died, I was concerned that my father killed her. And I have been fighting to get justice for this case ever since then. Reporter: The defense main tan -- maintains michelle mcneill died of a heart condition as the medical examiner ruled. She cited the cause of death, due to hypertension, cardiovascular disease. Reporter: And the prosecution can't prove that michelle was murdered at all. There is not evidence in this case that rises to the level of guilt beyond a reasonable doubt. Reporter: Now it is in the hand of a jury, five men and three women. Who began deliberating this afternoon. The story jurors heard from prosecutors over the course of the 149-day trial was almost too strange to believe. It began on an april morning in 2007 in the gated community southeast of salt lake city. A distraught sounding martin macneill called 911. My wife has fall in in the bathtub. Is she conscious? She is not. Reporter: When police showed up, mcneill said she passed out preparing the tub the they ruled it an accident. His daughters were suspicious and eventually became convinced their father had planned the whole thing persuading michelle, a former beauty queen to get a facelift with only one real goal in mind to overmedicate her during recovery and ultimately kill her. My mom was hesitant to get the surgery. She was talking to my dad saying that maybe we should delay the surgery. He got really angry at my mom and said no you cannot do that. If you don't have the surgery now, you are not getting it. Reporter: Daughter alexis kept close tabs on her mom and drugs sunny was taking. The valium at 12:00 a.M. The medication at 1:30 a.M. Gaer two percicets at 1:30 a.M., And one ambien. She is the most important witness for the prosecution because she monitored the drugs her mother was taking and kept a logbook. She was suspicious of her father because she found her mother overmedicated the first day sunny was home. And, alexis went back to school. The next day her mother was dead. Reporter: It was only years later that they were able to convince authorities to take another look at their mother's death. Once they did they learned a lot more about macneill and seemingly bizarre behavior. Starting with the 911 call where he either hung up on the dispatcher or was disconnected twice and provided the wrong address. Is she conscious? Reporter: This meant lost precious minutes in the fight to save michelle's life. Maybe most troubling. He said he couldn't remove his dying wife from the bathtub alone. Could you get her out of the water? I can't. I let the water out. Reporter: Doug daniels was called over when he claimed he needed a man's help to move the body. I could have got her out myself. Reporter: He testified that mcneill kept stopping cpr. Throw his hand in the air, twice. Say why, why would you do this? All because of a stupid surgery. The first responders said mcneill was loud and distracting. He was so disruptive to the crew that, as the fire chief, had removed him from the actual patient care scene. Reporter: Short low after that, mcneill allegedly asked his son's girlfriend to dispose of the drugs michelle had been taking. He asked you to flush the pills down the toilet? Yes. Did you do that? Yes. Did that request seem strange? At the time, yes. Drugs her plastic surgeon had not even wanted to prescribe. That was because martin indicated to me he was very concerned about his wife. She didn't handle pain well. If you will come forward. Most suspicious of all it turned out married martin mcneill had a girlfriend. My name is gypsy willis. Gypsy willis, mcneill met on line a year before his wife's death. Admitted under oath she and mcneill had been having an affair. Did the relationship become sexual? It did. When? Jaary, 2006 a awe how often were the two of you having sexual relations? We would see each other a couple times a month. Reporter: According to the prosecution, the pair exchanged calls on the day of michelle's death. And 15 texts on the day of her funeral. A funeral gypsy attended. You attended the funeral you said? I did. Did you speak to the defendant at the funeral? I spe spoke to him. Said hope you are all right. I am so sorry for your loss. She and martin mcneill pretend to meet for the first time. My father said -- oh, thank you. What's your name, I'm sorry? Oh. She said oh, my name is jillian. What got his daughters really suspicious. Shortly after michelle's death he moved gypsy into his home and announced she would now be the family's nanny. I expected her to be focused on the children. I expected her to -- do things related to that. To, to, cook, or clean, or take care of the children. What did you see her doing? My dad was cooking. She was sitting there staring at my dad. Reporter: Mcneill and jipsy were convicted in 2009 for stealing the identity, get this, one of the mcneill's own adopted daughters in an effort to wipe out gypsy's debt. Behind bars, numerous inmates CLAIMED that McTeam made incriminating statements. He said he gave her oxy and sleeping pills and got her to get in the bathtub. Reporter: One even testified that he confessed to the murder. You said I am getting away writ murtering my wife. All along, while mcneill may be an unsavory character he is no murderer. We probably shouldn't let's motions cloud our judgment. Does the defense plan to call witnesses. Reporter: The defense presented its case in a day with three witnesses offering what they say is an alibi. What do you make of the defense alibi claim? The defense tried to show that martin mcneill was not at the house the morning that his wife died. He couldn't have done it? Absolutely couldn't have done it. But there is a big hole there that they couldn't account for. Would you come forwar man their most important witness tried to explain why mcneill may not have been able to lift his wife from the tub. You can't get directly close to the tub to lift out. Reporter: But the defense avenue main argument, the prosecution did not prove michelle was murdered. You are saying there is a chance that the jury will say, we think -- he wanted it to happen. We think that he certainly could have didn't. But, we're not convinced beyond a reasonable doubt that sunny died at his hands. Yes. That's precisely what I am saying. If the jury acquits him they're probably thinking, he probably did it. But it's just not enough. I don't want to send this man to prison for murder. Just not absolutely convinced. Reporter: Nor his daughters who are convinced all they can dupe is wait as the jury deliberates their father's fate.
This transcript has been automatically generated and may not be 100% accurate.