(CNN) - A startling discovery in the case of the Georgia father whose son died after being left in the backseat of a blazing car for about seven hours.
Investigators now say someone searched "how long does it take for an animal to die in a hot car" on Justin Ross Harris's work computer.
A source tells HLN's Nancy Grace that police found the search history on computers seized from Harris' office, though it is unclear when the search was conducted or whether Harris did the search.
Harris is charged with murder and second-degree child cruelty in the death of 22-month old Cooper. Last week, he pleaded not guilty saying the whole incident was a horrifying mistake.
Witnesses describe Harris's reaction to discovering his son's body still in his car as distressed, and police say he had to be physically restrained at the scene…
"You could feel his sorrow and hurt over the situation."
"He just screamed, 'what have I done?' loudly. Obviously it was a bit dramatic, you know, hands in the air, looking towards the sky, 'What have I done?'"
Police say on the day of the incident Harris strapped Cooper into his rear-facing car seat and drove about half a mile to work after having breakfast at a local Chik-Fil-A.
According to authorities, when Harris arrived at work, he left his son in the car. Instead of taking him to the on-site daycare center as usual.
Investigators say Harris returned to the car at lunch and opened the driver's side door to put something inside. After work, police say, Harris left, and a few miles away he pulled into a local shopping center and called for help, but Cooper was already dead.
According to the medical examiner, the cause of death is likely hyperthermia, the temperature in the car potentially soaring above 130 degrees on that hot summer day.
Public sympathy for the father is waning as organizers behind a Change.org petition urging authorities to release Harris, withdrew their petition saying quote, "I think that based on the recent developments this petition is no longer relevant."
Harris is currently in jail waiting on a hearing set for next week. In the meantime, a funeral will be held for Cooper this weekend.
As Harris sits in jail, his wife, Leanna, has not discussed the case with the media.
Harris' attorney has not returned repeated calls from CNN.