Justin Ross Harris sits in Cobb County Magistrate Court in Marietta, Georgia July 3, 2014.
Justin Ross Harris sits in Cobb County Magistrate Court in Marietta, Georgia July 3, 2014. Reuters / POOL New

The Georgia Supreme Court on Wednesday overturned the murder conviction of a man accused of killing his 22-month-old son by leaving him in a sweltering sport utility vehicle because he wanted a child-free life.

The court, in a 6-3 decision, ruled that evidence of Justin Ross Harris's affairs should not have been admitted and may have unfairly swayed the jury in its 2016 decision.

Georgia Supreme Court Chief Justice David E. Nahmias reversed the convictions of murder and first-degree child cruelty in the case that had drawn international attention. Harris, 41, had been sentenced to life in prison without parole, plus 32 years.

It is now up to Cobb County District Attorney Flynn Broady, Jr. to decide whether to pursue a new trial. A spokesperson for the district attorney was not immediately available for comment.

Harris remains in prison on a 12-year conviction for exchanging lewd text messages and photos with an underage girl.

Harris had told police he forgot to drop his son Cooper off at day care and drove to work at Home Depot offices without remembering that Cooper was still in his car seat in June 2014.

Defense attorneys described him as a doting father and said the death was an accident.

Prosecutors argued that Harris was unhappily married and killed his son to free himself.