US dad gets life in prison for leaving son to die in hot car

A US man has been sentenced to life in prison after leaving his young son to die in a hot car while he sent sexually explicit messages from his office.

Justin Ross Harris was given the maximum sentence after lead prosecutor Chuck Boring said 22-month-old Cooper perished in "the most torturous, horrific, unimaginable way possible".

Harris had told the court he forgot to drop his son off at daycare on June 18, 2014 and didn't realize he left Cooper strapped into his car seat until leaving work.

Justin Harris with his son Cooper. Source: 7 News

The toddler was left for seven hours in the back seat of a car that heated up to almost 50C.

Prosecutors argued that Harris wanted to be free of family responsibilities, finding the 36-year-old had made internet searches about life without children and how to survive prison, and watched videos of animals dying in cars in the sun.

Justin Harris will spend the rest of his life in jail. Source: 7 News

A police detective also found Harris texted sexually explicit messages to six women, one of them as young as 17, while his young son was baking to his death.

A jury found Harris guilty three weeks ago with the sentencing hearing conducted on Monday.

Vision shows Harris getting breakfast with his son hours before the 22-month-old was found dead in the car. Source: 7 News

"The evidence that was presented at trial and the jury's verdict basically says it all," Boring said. "The evidence showed that this defendant was driven by selfishness and committed an unspeakable act against his own flesh and blood."

Harris, who was wearing an orange prison jumpsuit with his hands and ankles shackled, declined to speak at the sentencing. He frowned throughout the proceeding but did not show any emotion as the sentence was read out.

Police at the crime scene. Source: 7 News

The court had earlier seen vision of Harris with his son getting breakfast that morning.

The 36-year-old claimed he forgot his son because their routine changed that day, and said he failed to see the 22-month-old when he went back to the Hyundai to drop off shopping.

Justin Harris did not speak during his sentencing hearing on Monday. Source: 7 News

Harris's attorney, Maddox Kilgore, said he planned to file a motion for a new trial.

Harris will now die in jail after the possibility for parole was withdrawn.