(NewsNation) — Attorneys for Christopher Gregor, the New Jersey father accused of killing his 6-year-old son by forcing him to do abusive treadmill workouts, are adamant that the boy died from an infection and not from injuries sustained when he repeatedly fell off the treadmill.

Gregor’s defense attorney said in his closing argument on Wednesday that the prosecution did not present any evidence that Corey Micciolo died from blunt-force trauma and lacerations to his heart and liver as the autopsy determined.

Closing arguments began Wednesday after Gregor decided not to testify in his own defense. Gregor appeared before the New Jersey court Tuesday to announce he would not testify, which drew audible gasps from those watching in the courtroom.

On Wednesday, Gregor’s attorneys told the jury that prosecutors did not offer any police witnesses, doctors, or other experts to prove that the boy died in the manner medical officials maintain.

Instead, the defense says that Corey Micciolo died from an infection rather than Gregor causing any injury that led to his son’s death.

The prosecution is set to deliver its closing arguments Wednesday afternoon before the case goes to the jury.

Gregor was charged in his son’s death which took place in 2021 when surveillance video showed Gregor forcing his son to run at high speeds on a treadmill. The video shows Gregor continually increasing the speed on the treadmill, which forced his son to fall off the exercise equipment six times.

Gregor says he took Micciolo to the hospital after he woke up from a nap incoherent. Ultimately, Micciolo had a seizure and died at the hospital. Gregor is now on trial for the endangerment of the welfare of a child and first-degree murder.

Breanna Micciolo, the boy’s mother, said she reported suspected abuse more than 100 times in 18 months, but no action was taken before the child’s death.