The inmate witnesses who fear retaliation for "snitching" and were not identified while testifying in 4th District Court were housed in federal prison with Martin MacNeill while he was serving time for a previous identity fraud conviction.
Inmate #3 said he met Martin MacNeill at the "chicken coop" dorms at Texarkana Federal Prison and worked out with the man whom inmates referred to as "Doc."
"The only thing he said [about his wife's death] was that she drowned," the inmate testified.
During cross-examination, Inmate #3 confirmed he had lied about another inmate having threatened a federal prosecutor because he wanted to change prison compounds after he had informed in another case.
But he insisted he was telling the truth in the MacNeill case.
"I wouldn't travel all this way just to lie, because my life is already in danger anyways," the inmate said.
The inmate added that he wasn't being offered any deals or benefits in exchange for his testimony, and that his life could be threatened for breaking prison rules and "snitching" on a fellow inmate.
"Why are you here?" Deputy Utah County Attorney Jared Perkins asked.
"Because I got something to say and it's the truth," the inmate replied.
Another man, identified as Inmate #4, testified that he talked to "Doc" about his health while serving in prison together. He said Martin MacNeill initially told him that his wife was in a different prison serving time, but the inmate learned later that his wife had died. The inmate said he later asked him about his wife, after hearing rumors around the prison that a TV report had accused Martin MacNeill of murder.
"I said, 'Well, did you do it?' " the inmate testified. "He said, 'Bitch drowned.' "
But during cross-examination, defense attorney Randall Spencer asked the inmate if his client ever said directly that he killed his wife.
"He never told me he killed his wife," Inmate #4 answered.
The inmate also said he doesn't consider himself "a snitch," adding: "I'm just telling the truth about a conversation."
When the witness identified as Inmate #2 was asked by prosecutors if Martin MacNeill said that he killed his wife, the inmate testified: "He just said, 'They can't prove it was me.' "
Another inmate, scheduled to testify Wednesday, is expected to say that Martin MacNeill admitted to murder.
According to court documents, the man, identified only as Inmate #1, is expected to tell the jury that Martin MacNeill told him that he drugged his wife with Oxycontin and sleeping pills, then persuaded her to get into the bathtub, where he held her underwater for a little while "to help her out."
Prosecutors claim Martin MacNeill killed his wife in order to continue an extramarital affair with another woman, 37-year-old Gypsy Willis. He is charged with first-degree felony murder and second-degree felony obstruction of justice.
According to court records filed before the trial began, the federal inmates were not offered any substantial benefits in exchange for their testimony because state investigators and prosecutors have no authority over federal inmates or sentencing.
A Utah County Jail inmate also is expected to be called to the witness stand Wednesday. That man did receive a plea deal in a theft case in exchange for his cooperation, but according to court records he told investigators he wanted to testify because of his "morals."
"I don't want him out on the streets," he allegedly told investigators, referring to Martin MacNeill. "I don't want him to victimize another person like that. I mean, his wife, if he can kill his own wife, he can kill a random person."
On April 11, 2007, Ada MacNeill, then 6, found her mother fully clothed and face-up in the bathtub, according to the girl's interview with the Children's Justice Center in 2008.
The child was sent by her father to a neighbor's house to get help, and eventually Michele MacNeill was pulled from the bathtub by a neighbor and Martin MacNeill. The two attempted CPR before medical crews arrived.
Those medical crews also attempted to perform CPR and other life-saving efforts before Michele MacNeill was taken to an American Fork hospital, where she was pronounced dead.
After an autopsy in 2007, her manner of death was ruled "natural," the result of "chronic hypertension and myocarditis, which are capable of causing acute unexpected arrhythmia and sudden death.
But investigations say Martin MacNeill called the medical examiner multiple times and gave misleading information. In 2010, in a new investigative report, Chief Medical Examiner Todd Grey changed the cause of death to the combined effects of heart disease and drug toxicity. The manner of death was changed to "undetermined."
Also Tuesday, Utah County Attorney's Office investigator Jeff Robinson took the stand, and testified that Martin MacNeill could drive anywhere between his home, Ada's school and his work within a five-minute span. The testimony apparently was intended to poke holes in Martin MacNeill's "alibi defense," in which he claims he was at work when his wife died and couldn't have killed her.