Father Charged With Felony Murder in Son's Heat-Stroke Vehicle Death Family claims it was an honest mistake, but police disagree.

 -- A Georgia father has been charged with felony murder in the death of his 22-month-old son after the boy was left inside a mini-SUV for hours on a sweltering day.

The man’s family claims it was an honest and tragic mistake. But police disagree – and Justin Ross Harris, 33, now faces heightened charges in Cooper’s heat stroke death, a case that has drawn outrage from people who believe the man has already suffered enough.

Harris buckled his son Cooper into his car seat Wednesday before heading to his job as a Web developer at a Home Depot corporate office near Atlanta. On the way, Harris was supposed to drop off his son at daycare.

He never did.

The temperature outside reached 92 degrees by noon.

Spotting and Treating Heat-Related Illness

Ky. Football Coach Acquitted in Player's Death

Fran Crippen Death: Likely Heat Stroke or Heart

Hours passed. As Harris was driving home for the night, he noticed his son still in the backseat and pulled into a shopping center parking lot. Witnesses say he rushed to try to save Cooper.

“He kept saying, ‘What have I done? What have I done,’” witness Dale Hamilton told ABC affiliate station WSB-TV. “He laid his son on the ground and started doing CPR, trying to resuscitate him. Apparently, the child wasn’t responding.”

After searching Harris’s office, police arrested the grieving father and charged him with felony murder and child endangerment.

“Until we more or less run out, a lot of the information that we are having to track down, right now these charges will stand,” Cobb County Police Sgt. Dana Pierce said.

The arrest has caused outrage, with some saying the father simply made a mistake, although others agree with police. Supporters have raised more than $18,000 for his defense.

“The justice system can’t punish Ross worse than he is punishing himself,” one commenter wrote.

“It will only cause more pain for a grieving family,” another wrote.

An average of 38 children die across the United States annually after being left in a hot car, with 44 deaths reported nationally last year, according to kidsandcars.org, a national nonprofit devoted to vehicle safety. In Atlanta, more than 22 children have died this way since 1990.

Public safety advocates say these are usually accidents and happen to the most loving and protective parents of every color and socioeconomic background.

Cooper’s death marked the second vehicle heat stroke death involving a child last week. A Florida man, Steven Lillie, faces aggravated manslaughter charges in the June 16 death of his 9-month-old daughter, Anna Marie.

In Harris’ case, police feel strongly about the murder charge, ABC’s Chief Legal Affairs Anchor Dan Abrams said.

“We don’t know exactly what evidence they have, but they’ve executed a search warrant. And it’s not uncommon for computer-related searches to yield information,” Abrams said. “Whatever the evidence is, the authorities believed it warranted bringing charges very quickly.”