Justin Ross Harris’ Prosecutor Speaks Out on Hot Car Murder Conviction: Dad Thought He’d Get Away with It

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Prosecutors were not surprised to learn Monday that Justin Ross Harris, recently convicted of murdering his toddler son in Georgia by leaving him to die in a hot car, will spend the rest of his life in prison. As lead prosecutor Chuck Boring tells PEOPLE, it’s not just a prison sentence that matches the law — it’s one that matches the nature of the crime.

“In this case, it was nothing more than this defendant, his own selfish desires outweighed those of his child’s life,” says Boring, the senior assistant district attorney in Cobb County, Georgia, where Harris was arrested almost immediately after his son, Cooper, was killed in June 2014.

“He chose a way to kill this child that would be agonizing and torturous, and he did it because he thought he had concocted a crime that he could get away with,” Boring tells PEOPLE.

Expanding on that, Boring explains that he believes Harris chose to kill Cooper with a hot car because it is a widely known — and typically accidental — manner of death for children.

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“I think our main concern was convincing people that somebody’s capable of this type of evil,” Boring says, drawing a line between an accident that a juror could understand and imagine and what happened to Cooper.

But “this is so not that case,” Boring says of comparing Harris’ prosecution to an accidental hot car death.

At trial, he and his team cast Harris as a callous father and sexually deviant husband, undercutting the defense’s claims that Cooper’s death was a tragic accident. Instead, the state argued, evidence showed Harris visited online communities about the “child-free” lifestyle and “people who die,” searched strange phrases on Google such as “how to survive in prison” and even researched the deadly effects of being in a hot car.

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Further, prosecutors claimed that Harris sexted with multiple women, including on the day Cooper died, and had visited prostitutes — behavior the defense dismissed as irrelevant to a possible motive for murder.

“He failed. … He is responsible. Only him. Nobody else,” Harris’ defense attorney, Maddox Kilgore, said at trial. “And he has acknowledged that from day one. He is responsible. But responsible is not the same thing as criminal. It is not.”

Harris’ ex-wife, who is Cooper’s mother, also testified on his behalf and has called him a “wonderful father.” (She defended him following his conviction as well.)

But prosecutors thought the evidence was persuasive. The jury agreed, finding Harris guilty in November on eight felony counts, including malice murder. On Monday, Harris was sentenced to life in prison without parole as well as an additional 32 years.

Kilgore has said Harris will appeal the verdict, though he has not specified the grounds. (Harris did not speak at his sentencing, and Kilgore has not responded to PEOPLE’s repeated inquiries.)

Boring says the timeline for any appeal is hard to estimate, but it will be a while. Because the case was heavily litigated, prosecutors know some of the issues that may be raised.

Boring says the intense scrutiny the case was under, from both the public and media, made the state work as hard and as diligently as possible. But he says they had “no clue what this was going to become” when Harris was first arrested.

“This is the first case that I’ve ever been a part of like this, in the social media age,” Boring says. “It’s constant.”

He says that had its perks, allowing officials to learn about prospective jurors, and even helping them prepare for trial because video of each day was so readily available for review. But the prosecution was “draining,” too, Boring says — not so much financially as in manpower and emotions.

So far in his career, it’s been a once-in-a-lifetime trial that isn’t likely to be repeated soon.

With a small laugh, he says, “Never again.”