Kilgore said he himself had forgotten boxed-up leftovers, a comparison on which the prosecution seized. Someone might remember that they left spaghetti in the car after 30 minutes, said Assistant District Attorney Chuck Boring.
But Harris not only forgot his child, he got an e-mail from his son's day care during the day and at one point went to the vehicle to place light bulbs inside, never once remembering Cooper, the prosecutor said.
"I think it's remarkable he didn't stick his head in that car," Boring said. "He knew what he was going to find."
In what might be a harbinger, the defense repeatedly asked witnesses about being deaf in one ear, perhaps indicating that Harris might not have heard his child in the back seat when he got out of the car and when he returned to it.
"He is deaf in one ear or mostly deaf," a friend testified about Harris. "I always have to go to the other side of his head to talk to him," said Winston Rowell Milling.
'Fearful that this could happen'
Among the details police have released is that Harris and his wife told them they conducted Internet searches on how hot a car needed to be to kill a child.
Also, five days before Cooper died, Ross Harris twice viewed a sort of homemade public service announcement in which a veterinarian demonstrates on video the dangers of leaving someone or something inside a hot car.
Leanna Harris told police that she had recently seen a story on a state initiative aimed at reminding people not to leave children in cars and that it was a fear of hers, Stoddard said.
Ross Harris "stated that he recently researched, through the Internet, child deaths inside vehicles and what temperature it needs to be for that to occur," police said, adding that Harris told investigators "he was fearful that this could happen."
During questioning, Leanna Harris "made similar statements regarding researching in car deaths and how it occurs," police said.
The time frame for the alleged research remains unclear.
Cooper was buried Saturday in Tuscaloosa, Alabama.
The Cobb County Medical Examiner's Office determined that the child's cause of death was "consistent with hyperthermia and the investigative information suggests the manner of death is homicide," according to a Cobb County Department of Public Safety statement.
The Medical Examiner's Office is waiting for toxicology test results before making an official ruling on the toddler's death.
At the boy's funeral, Leanna Harris said she loves her husband and stands by him.
"Am I angry with Ross?" Leanna Harris told mourners. "Absolutely not. It has never crossed my mind. Ross is and was and will be, if we have more children, a wonderful father. Ross is a wonderful daddy and leader for our household. Cooper meant the world to him."