Obsessed with seeking sex outside his marriage, prosecutors say, a Georgia man left his toddler son to die inside a hot SUV so he could "escape from one life into another."

Prosecutors opened their case Monday against Justin Ross Harris, who is charged with malice murder and other crimes in the June 2014 death of his 22-month-old son, Cooper. Assistant District Attorney Chuck Boring called Harris a deceptive man who saw his wife and child as obstacles to fulfilling his sexual desires.

"This case is about death, deception and a double life," Boring told a jury evenly split between men and women during his opening statement Monday.

Harris' defense attorneys will get their first chance to speak to the jury Tuesday morning. The defense team's opening statement got pushed back after court was delayed for 90 minutes late Monday afternoon. Superior Court Judge Mary Staley Clark recessed for the evening without giving an explanation.

Authorities say Cooper died after sweltering for seven hours in the parking lot of the Home Depot office where his father worked as a computer technician in the Atlanta suburb of Cobb County. Citing pretrial publicity, the judge moved the case 275 miles to Brunswick, on the Georgia coast.

Cooper Harris who died after being left in his father's car. (Facebook)

Harris' attorneys have previously called the boy's death a tragic accident. Harris told police he watched cartoons with his son that morning, took him to breakfast at a Chick-fil-A restaurant and kissed Cooper while strapping him into his car seat. But Harris said he forgot to drop his son off at day care and drove to work, forgetting the boy was in the back seat.

Boring told the jury Harris' account doesn't make sense. He said the minutes before leaving his son to die, Harris posted an online message that read: "I love my son and all, but we both need escapes."

He said Harris and his son ate breakfast just over half a mile from the Home Depot office where Harris worked as a computer technician, and Harris parked his SUV by backing up between two vehicles -- which would have required looking over his shoulder toward the backseat where his son sat.

Later that day, Harris opened his vehicle to toss in a bag of lightbulbs he bought during his lunch break, Boring said. After leaving work, he drove a few miles to a shopping center without stopping, the prosecutor said, though police later reported the SUV reeked from "sweat, a dirty diaper, the smell of death."

"Hold this man responsible for trying to escape from one life into another by killing a child in one of the most horrible, unimaginable ways possible," Boring told the jury.

Boring said on the day Cooper died, his father sent more than 30 messages on his phone "mostly to women, mostly about sex."

He said Harris was unhappy in his marriage to the boy's mother and was obsessed with finding other sex partners. The month before his son died, Boring said, Harris met a prostitute for sex at a hotel. He had also been trying to persuade an underage, 17-year-old girl to send him a photo of her genitals. Harris was also charged for sending the girl sexually explicit text messages and photos.

Sixteen total jurors -- eight men and eight women -- were seated Monday morning to hear the case. Four of them will serve as alternate jurors, who will have a final say in the trial only if one more of the 12 main jurors are dismissed. The judge did not specify which jury members were alternates.

Harris, who moved to Georgia from Tuscaloosa, Alabama, in 2012, faces life in prison if he's convicted of murder. Prosecutors decided not to seek the death penalty.