An Ohio man who admitted slamming a 15-month-old girl on the floor, ultimately causing her death, changed his plea this week from not guilty by reason of insanity to guilty.

Michael Mayor, 34, changed his plea in a hearing on Thursday, according to WHIO.

MIchael Mayor, 34, was arrested weeks after baby Vivian Gardner’s death in December 2024. Mayor’s wife, who provides babysitting services in the Piqua area, was babysitting the toddler and left her in Mayor’s care while she took other children to school on December 5, as CrimeOnline reported.

When she returned, she thought the child was asleep, but when she didn’t wake up by 3 p.m., she called 911, telling dispatchers she was “pale, had bruises on her head, and she was unsure where they came from,” a police report said.

The child was ultimately flown to Dayton Children’s Hospital for treatment, where a doctor said she had a fracture in the rear of her skull, a subdural hematoma, and other “complex” injuries that were caused by a “massive impact.”

She died on December 19.

In an interview, Mayor told detectives that the little girl wouldn’t stop crying when he was trying to put her down for a nap.

“He stated he ‘shook’ her and when she cried louder, he began to ‘slam’ her on the floor of the bedroom,” the police report said. “He stated this was not done on the blankets and he did this several times until she stopped crying.”

At that point, the report says, Mayor said he thought she had fallen alseep, so he walked away.

He was charged at that time with three counts of murder, felonious assault, and two counts of endangering children.

According to the plea deal, prosecutors dropped all but one count of murder, WHIO said. Sentencing has been set for August 5, and Mayor faces 15 years to life at that time, court records say.