PROVO, Utah — A jury convicted a doctor of murder Saturday in the death of his wife six years ago, bringing an end to a trial that became the nation’s latest true-crime cable TV obsession with its tales of jailhouse snitches, forced plastic surgery, philandering, and betrayal.
Martin MacNeill was accused of knocking out Michele MacNeill with drugs after cosmetic surgery, then leaving her to die in a tub like one that was displayed during the trial.
Prosecutors said that he may have held her underwater for good measure and that he did it to begin a new life with another woman.
Michele MacNeill’s daughters and other relatives let out a loud yelp before shedding tears as the jury delivered its verdict.
‘‘We’re just so happy he can’t hurt anyone else,’’ said Alexis Somers, one of his older daughters. ‘‘We miss our mom. . . . But that courtroom was full of so many people who loved her.’’
Martin MacNeill, 57, showed little emotion when the verdict was read. He hugged his lawyer afterward and said, ‘‘It’s OK.’’
He faces 15 years to life for first-degree murder when he is sentenced Jan. 7. He also was found guilty of obstruction of justice, which could add one to 15 years. MacNeill was led by deputies back to Utah County jail.
Randy Spencer, one of the defense lawyers, said he was disappointed, then declined further comment.
The chief prosecutor, Chad Grunander, said the largely circumstantial case was the most difficult he ever brought to trial and that many prosecutors would not bother trying, especially with medical examiners unable to produce a finding of homicide.
‘‘It was an almost perfect murder,’’ Grunander said in his closing argument, asserting MacNeill ‘‘pumped her full of drugs’’ that he knew would be difficult to detect once she was dead.
An early mistress of MacNeill’s testified he once confided he could induce a heart attack in someone that would appear natural.
After deliberating for 11 hours, the jury issued its guilty verdict to murder and obstruction of justice shortly after 1 a.m. Saturday.
The case shocked the Mormon community of Pleasant Grove, 35 miles south of Salt Lake City, and captured national attention because the defendant was a wealthy doctor and a lawyer, a father of eight in a picture-perfect family, and former bishop in his local congregation of the Church of Jesus Christ of Latter-day Saints.
Defense lawyers contend Michele MacNeill died of natural causes. They believe she had a heart attack and fell headfirst into the tub and said the autopsy showed she had an enlarged heart, a narrowing of the heart arteries, and liver and kidney deterioration.
‘‘There’s simply no proof’’ of homicide, Spencer said. ‘‘The prosecution has presented to you their cherry-picked portion of the evidence.’’
He called the testimony of a handful of prison inmates angling for early release doubtful. The men who spent time behind bars with the doctor testified he had acknowledged killing his wife — or suggested that investigators could never prove he did it.
Their testimony was the only direct evidence of murder, Grunander said.
MacNeill’s lawyers argued he would never admit murder to strangers in prison.
MacNeill was medical director of the Utah State Development Center, a residential center for people with cognitive disorders, who moonlighted in other medical jobs, once consulting for a laser hair removal clinic.
MacNeill had a law degree but was not known to have practiced law and has since surrendered his law and medical licenses.
The highlight of the three-week trial was a mistress who MacNeill introduced as a nanny within weeks of his wife’s death. His older daughters quickly recognized Gypsy Willis as his secret lover and said her mother had been arguing with her husband about the affair.