Utah Doc's Youngest Daughter Recalls Finding Mom Submerged in 'Brown' Water

Oct. 29, 2013— -- Dr. Martin MacNeill's youngest daughter recalled finding her mother submerged in brown bath water the day she died, according to video testimony played today for jurors at the Utah doctor's murder trial.

Ada MacNeill was 6 years old when she found her mother, Michele MacNeill, unconscious in the bathtub on April 11, 2007.

In the video interview, recorded in 2008, Ada repeatedly tells the interviewer that she does not want to "talk about" her life in Utah, however after careful questioning, she offered some insight into the day her mother died.

"She was just laying down in the bathtub," Ada told the interviewer at the Children's Justice Center in Utah. "She was just trying to wet her hair."

She added that her mother was "all the way" in the bathtub and that the water "was almost brown and stuff."

Later in the recording, the interviewer asked Ada about her father, Dr. Martin MacNeill.

"How do you feel when you are around your dad?" the interviewer asks.

"I don't want to talk about it," Ada replied in a whisper.

The video recording was the only testimony allowed from Ada, now 12 years old, at her father's murder trial in Provo, Utah, after Judge Derek Pullan ruled the girl may have "planted or distorted" memories.

The defense was given an opportunity to cross-examine Ada in person after the video was played today, but they declined.

Mistress Sent Doctor Steamy Photos

Earlier today, prosecutors confronted MacNeill's purported mistress with photo messages she allegedly sent the Utah doctor just one day after his wife died -- including one steamy picture that showed her back and buttocks.

Gypsy Willis conceded that one photo is "a little bit suggestive" when prosecutors asked her to look at the messages she sent MacNeill on April 12, 2007.

On her second day on the stand, Willis said her relationship with MacNeill remained sexual, even after he hired her to be a live-in nanny for his younger children.

Live Coverage: Dr. Martin MacNeill's Trial

Rachel MacNeill, one of the Utah doctor's older daughters, testified last week that Willis did little to help with the children and instead "was just goo eyes at my dad." Willis denied the claim.

"My response is that when the adult children were home, I deferred to them and went back to studying my nursing," Willis said. "I did actually help with the children."

The relationship between MacNeill and Willis moved full-speed ahead, and by late June, the couple were looking for wedding rings online, prosecutors noted. During a trip to Wyoming in July, just months after his wife died, MacNeill proposed to Willis at a restaurant with a four-and-a-half carat diamond ring.

Willis struggled to remember the details of the proposal when asked by prosecutors.

"It's been so long. This relationship has been over a very long time," she said.

Willis testified on Friday that she met MacNeill, 57, a married father of eight children, online around November 2005, however their relationship did not turn sexual until January 2006, she said.

"We would see each other about a couple times a month. There were months when we didn't see each other. It was a very casual thing," Willis said.

Prosecutors allege MacNeill drugged and drowned his wife, Michele MacNeill, 50, on April 11, 2007, so he could pursue a relationship with Willis.

Prosecutors presented phone records on Friday that they said indicated the couple exchanged text messages during Michele MacNeill's funeral, which they both attended.

"This was a very informal, discreet thing," Willis said of her relationship with MacNeill. "I think he was trying to keep it quiet."

Willis was the latest in the prosecution's arsenal of star witnesses to testify at the trial. Last week, MacNeill's oldest daughters, Alexis Somers and Rachel MacNeill, testified.

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

MacNeill's defense lawyers said heart problems were a contributing factor in the death of the former beauty queen and mother of eight, and that the once-prominent doctor isn't a murderer.

The medical examiner has never determined a cause of death for Michele MacNeill.