An Orange County father has now been charged with murder for forcing his 5-year-old son to do push-ups and squats as punishment until he collapsed and later died.

Darell Avant Sr. was originally arrested Wednesday on child abuse charges. The Orange County Sheriff's Office announced Friday that it was upgrading the charges against Avant to first-degree murder.

"I have young children at about the same age as Darell, and it's very tough to look at this on a daily basis at work and then not look at your own children and say that you love them," said Detective Kevin Wilson, with the Orange County Sheriff's Office.

Deputies said Avant took his son, Darell Avant Jr., out of school Wednesday after the boy was acting up, and brought the boy back to his apartment on Burroughs Court, located off Hiawassee Road near Silver Star Road.

According to an arrest report, Avant Sr. admitted to deputies that he smacked the boy's behind a few times and ordered him to do push-ups and squats for about 20 minutes.

"Doctors say that this was a beating that took a long period of time," Wilson said.

The boy then said he didn't feel so well, and complained of being hot and dizzy before falling unconscious. Deputies said Avant Sr. called a neighbor for help, and the neighbor called 911.

Avant Jr. was later pronounced dead Wednesday evening at the home.

Upon conducting an autopsy, Orange County Medical Examiner Dr. Jan Garavaglia said there were bruises and contusions on the boy's chest, stomach, arms and back. She ruled the death a homicide, saying Avant Jr. died from internal injuries due to multiple blunt force trauma.

The boy's mother, who is separated from Avant Sr., indicated that there were no bruises on her son when he went to school Wednesday morning. Deputies said she was unable to pick her son up from school, so administrators called the boy's father.

A judge decided Friday to place a 1-year-old also living with Avant Sr. in the sole custody of the child's mother.