(CN) — A former Cobb County medical examiner testified Tuesday that Cooper Harris, the toddler who died after his father left him all day in a hot SUV, died a slow death.
Brian Frist said the cause of the child's death was hyperthermia due to excessive heat.
Though his initial report said the manner of Cooper's death was undetermined, on the stand, Frist said he believes it was a homicide.
"He died as a result of someone else's actions," Frist said.
As Frist described Cooper's death, defendant Justin Ross Harris appeared to be crying, burying his head in his hand and wiping his eyes and nose.
Harris is accused of intentionally leaving Cooper in his car in June 2014.
Abrasions on Cooper's body showed that Cooper probably struggled to try to get out of his car seat, Frist said. He was slumped to the left side of the car seat.
Cooper's abdomen had a green discoloration, which Frist said showed that his internal organs had become decomposed.
Earlier on Tuesday, Martin Jackson, an investigator with the Cobb County medical examiner's office, testified that Cooper's body was in a state of moderate rigor mortis, meaning investigators were able to move his arms and legs.
He said he moved Cooper's body onto a sheet to complete the examination because the pavement was so hot.
"There was an odor of urine present," Jackson said.
Jackson said the day after Cooper's death, he spoke with Leanna Harris and asked her for her son's medical records.
He described her as uncooperative, saying that she had already given them to someone else and he would need to get them from that person. Jackson said he ended up having to subpoena the records.
He also said he was unaware at the time that Ross Harris had been arrested and charged in Cooper's death.
He said all he knew was that Ross Harris was being questioned.
Later on Tuesday, a witness testified that Cooper Harris's father acted "calm and nonchalant" in the Cobb County jail after being charged in the death of his son.
Mark Wilson, 23, encountered defendant Justin Ross Harris June 18, 2014, in the holding area of the jail, where Wilson was serving a 24-hour sentence for a DUI. They sat together for over two hours.
Prosecutors showed video footage of Harris and Wilson sitting next to each other in the holding area. Harris was reclining, with his left arm resting on the back of the chair. There was no audio.
"When he first walked in, he looked at everyone and said 'what's up guys,'" Wilson recalled.
Larry Lewellen, a forensics toxicology expert, testified that he tested Cooper Harris' blood and found no evidence of drugs. Kasey Wilson, a crime lab scientist, tested Cooper's blood for alcohol and found nothing.
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