The jury deliberated for about six hours before returning its verdict against Melvin Morse, 60.
Morse was charged with three felonies — two for alleged waterboarding and one for alleged suffocation by hand. He was convicted of one felony — waterboarding in the bathtub — and five misdemeanors. Jurors reduced the second waterboarding charge to a misdemeanor and acquitted Morse of the suffocation charge.
Morse showed no reaction as the verdict was read. He was ordered to surrender his passport and will remain out on bail until his sentencing, set for April 11.
Morse faces a maximum of 10 years in prison, but a lesser punishment is likely under state sentencing guidelines. Each misdemeanor carries a maximum of one year in prison but typically results in probation. The felony reckless endangerment conviction for waterboarding carries a maximum of five years in prison but a presumptive sentence of 15 months.
Prosecutor Melanie Withers said she was "very gratified" by the verdict, and that she was on her way to speak with the victim, now 12 years old.
Morse declined to comment and referred questions to his attorneys.
"He maintains his innocence to this day," said attorney John Brady.
Morse's lead defense attorney, Joseph Hurley, said he planned to appeal.
The girl and her mother, Pauline Morse, testified that Melvin Morse used waterboarding as a threat or a form of punishment. Waterboarding has been used in the past by U.S. interrogators on terror suspects to simulate drowning. Many critics call it torture.
Defense attorneys argued that "waterboarding" was a term jokingly used to describe hair washing the girl did not like.
But Withers portrayed Melvin Morse as a brutal and domineering "lord and master" of his household, abusing the girl for years while her mother acquiesced in silence. Pauline Morse, 41, said she chose to ignore the abuse and was afraid of "undermining" Melvin Morse. She also testified that she did not have a close relationship with the girl for the several years that encompassed the waterboarding, and that she did not pay her much attention.
Pauline Morse pleaded guilty last year to misdemeanor endangerment charges and testified against Melvin Morse. She was not in the courtroom Thursday.
Hurley was highly critical of a decision by the judge to allow jurors to review videotaped interviews of the victim and her younger sister by authorities in August 2012. He said the unsworn statements improperly prejudiced the jury.
"The disappointment is in the court allowing the instant replay of the interviews that were the heart of the state's evidence," Hurley said, adding that replaying the unsworn statements left jurors with an unchallenged version of the state's evidence fresh in their minds.
"That really is powerful evidence under the circumstances in this case," he said. "There will be an appeal on that basis."
Hurley said another basis for appeal is what he described as inappropriate statements made by Withers in her closing arguments, including telling the jurors that they could ask for evidence to be sent back to the jury room if they wanted to review it.
Hurley also noted that prosecutors were allowed to present photographs and other evidence of alleged abuse for which Morse was not charged, including one photograph, shown repeatedly by prosecutors, of the tearful victim with her fingers in both nostrils. Morse said he took the photograph to show the girl's mother what he described as an act of defiance after he had slapped the child for sticking one of her fingers in her nose.
"What the prosecution was trying to do was skin him alive and tar-and-feather him with 'he's a cruel, bad person," Hurley said.
Morse was charged with endangerment and assault after the girl ran away in July 2012 and told authorities of waterboarding and other abuse.
The girl fled her home and went to a classmate's house the morning after Morse grabbed her by the ankle and dragged her across a gravel driveway into the home, where she was spanked and warned of worse punishment the next day. When investigators questioned the girl, then 11, she told them about what she called waterboarding.
Morse was convicted of misdemeanor assault and child endangerment charges for the driveway incident, which he acknowledged he could have handled better.
Morse, whose medical license was suspended after his arrest, has written several books and articles on paranormal science and near-death experiences involving children. He has appeared on shows such as "Larry King Live" and the "The Oprah Winfrey Show" to discuss his research, which also has been featured on an episode of "Unsolved Mysteries" and in an article in "Rolling Stone" magazine. Morse denied police claims that he may have been experimenting on the girl.
Prosecutors argued that in addition to waterboarding, Melvin Morse subjected the girl to other abuse, including forcing her to stand with arms outstretched for hours at a time, confining her to room, where she had to use her toy box or closet as a toilet, and alternately depriving her of food or force feeding her until she vomited.
The felony conviction against Morse stems from an incident in which the girl said she was waterboarded in the bathtub as punishment for vomiting into a cat's litter box after being forced to drink too much milk.
The girl and her younger sister remain in foster care but are allowed supervised visits with Pauline Morse. Pauline Morse admitted that she hoped her cooperation with prosecutors would bolster her chances of being reunited with her daughters. Her supervised visits with the girls were recently increased from once a week to twice a week.
"She's optimistic and she's moving forward," said her public defender, Dean Johnson.
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