On June 18, 2014, Justin Ross Harris' son Cooper died of hyperthermia at 22 months old after spending hours buckled in his car seat in the back of an SUV parked outside his father's workplace
Cooper Harris
Cooper Harris (left) with his dad, Justin Ross Harris.

The Georgia Supreme Court has overturned the 2016 murder conviction of Justin Ross Harris, who had been found guilty of intentionally leaving his 22-month-old son to die in a hot car.

On June 18, 2014, Harris' son Cooper died of hyperthermia after spending seven hours buckled in his rear-facing car seat in the back of an SUV parked outside of his father's place of work at a Home Depot corporate office in Marietta, Ga.

Prosecutors argued at the trial that Harris killed his son so he could be free to have sex with as many women as possible. They also claimed that he exchanged sexual text messages with six different women on the day his son died.

According to court documents released Wednesday and obtained by PEOPLE, the conviction was overturned because Georgia's highest court found that much of the evidence presented in 2016 "was needlessly cumulative and prejudicial" and should have been excluded from trial.

Cooper Harris
Cooper Harris (left) with his dad, Justin Ross Harris.

"Because the properly admitted evidence that Appellant (Harris) maliciously and intentionally left Cooper to die was far from overwhelming, we cannot say that it is highly probable that the erroneously admitted sexual evidence did not contribute to the jury's guilty verdicts," Chief Justice David Nahmias wrote in the court's 6-3 decision. "We therefore reverse Appellant's convictions on the counts charging crimes against Cooper."

"Through extensive evidence about Appellant's extramarital sexual relationships — which included sending graphic sexual messages and pictures to multiple women, including minors, and hiring a prostitute — the State convincingly demonstrated that Appellant was a philanderer, a pervert, and even a sexual predator," the documents read.

However, "this evidence did little if anything to answer the key question of Appellant's intent when he walked away from Cooper," the decision continues.

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Still, the court upheld the sexual crimes charges against Harris, which the defendant did not challenge.

During the murder trial, Harris was also found guilty of one count of exploitation of a child and two counts of dissemination of harmful material to a minor, for his involvement with a girl who was 16 years old at the time. He will remain in prison for these charges.

Harris' defense team argued that Cooper's death was a tragic accident, and that Harris did not intend to kill his young son.

In a statement obtained by NBC News, Harris' defense attorney Carlos J. Rodriguez said, "We are thrilled that the Georgia Supreme Court has reversed Ross's murder convictions, but make no mistake — this decision comes as no surprise. Inadmissible evidence can lead juries to wrongfully convict an innocent person. Today's decision mirrors the very same points that we made to the trial judge, and we were right. I only wish the trial court had listened."

The Cobb County District Attorney's Office said in a statement to PEOPLE that they plan to file a motion for reconsideration in this case.