COBB COUNTY, Ga. – Many questions remain unanswered in the Cobb County death of a toddler left stranded for hours in the backseat of his father's car.

The boy's father, Justin Harris, has been charged with murder and cruelty to children in the death of 22-month-old Cooper Harris.

Police and prosecutors have refused to say what evidence they've uncovered that suggests Cooper's death was a crime and not an accident.

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Harris was denied bond and will remain locked up at least until his next court appearance July 15.

A man who witnessed the moments after Harris discovered his son's lifeless body says the father's pain seemed raw and very real.

"I think it is impossible for this to have been intentional," said Leonard Madden. "There's no way it would have been intentional – especially from the father's reaction. You could feel his sorrow and his hurt because of the situation. I think it was insanity for him to be charged with murder."

Harris has received tremendous support online. More than 10,000 people have signed an online petition urging the district attorney to drop the charges. They've also donated thousands of dollars towards his son's burial.