ATLANTA (CNN) -

Surprising claims came to light during a hearing Thursday for a Georgia man whose toddler son died after being left in a hot car, a man prosecutors sought to portray as an unfaithful husband who wanted a child-free life.

Among the most shocking allegations: Justin Ross Harris messaged six women, sending and receiving explicit texts -- some including nude images -- from work while his 22-month-old was dying, a detective testified at the hearing.

Harris' attorney repeatedly objected to Cobb County, Georgia, police Detective Phil Stoddard's testimony claiming that Harris sexted the women -- one of whom was underage at the time -- but the judge allowed it.

Police say Harris, 33, left his toddler, Cooper, strapped into a car seat under a baking sun for seven hours while he went to work June 18. Records show that the mercury topped 92 that day, and police say the temperature was 88 degrees when the boy was pronounced dead in a parking lot not far from his father's workplace.

At the hearing, Cobb County Chief Magistrate Frank Cox found probable cause for the case against Harris to move forward with respect to murder and child cruelty charges.

"For him to enter the car ... when the child had been dead and rigor mortis had set in, and the testimony is the stench in the car was overwhelming at that point in time, that he -- in spite of that -- got in the car and drove it for some distance before he took any action to check on the welfare of his child, I find there is probable cause for the two charges contained in the warrant," Cox told a packed courtroom.

The judge denied bail for Harris, who has pleaded not guilty.

In addition to the charges he faces in connection with his son's death, Harris may also be charged with felony sexual exploitation of a minor and misdemeanor illegal contact with a minor, Stoddard said.

Internet searches

The detective also testified about Internet searches that could raise eyebrows given the context of the case.

Before his son's death, Harris had visited a Reddit page called "child-free" and read four articles, Stoddard said. He also allegedly searched how to survive in prison.

Among the other details police have released is that Harris and his wife, Leanna Harris, told them they looked up how hot a car needed to be to kill a child.

Five days before Cooper died, Ross Harris twice viewed a sort of homemade public service announcement in which a veterinarian demonstrates on video the dangers of leaving someone or something inside a hot car.

Leanna Harris told police that she had recently seen a story on a state initiative aimed at reminding people not to leave children in cars and that it was a fear of hers, Stoddard said.

Ross Harris "stated that he recently researched, through the Internet, child deaths inside vehicles and what temperature it needs to be for that to occur," police have said, adding that Harris told investigators "he was fearful that this could happen."

During questioning, Leanna Harris "made similar statements regarding researching in car deaths and how it occurs," according to police.

The time frame for the alleged research remains unclear.

'I felt his pain; I even wept'

Thursday's probable cause hearing was expected to last 90 minutes; it stretched for some three hours.

A good chunk of that time was spent discussing how Ross Harris acted after he pulled into a shopping center asking for assistance with his son.

Witnesses told police they heard "squealing tires, and the vehicle came to a stop," Stoddard testified. Harris got out of the car yelling, "Oh, my God, what have I done?" Stoddard said.

The 33-year-old father then stood there with a blank look on his face, the detective said. When a witness told Harris his son needed CPR, Harris went to the other side of his vehicle and made a phone call, apparently to tell someone his son was dead, a witness told police, according to Stoddard.

Harris never called 911, and when an officer told him to get off his phone, he refused and even said, "F*** you" before an officer took his phone and handcuffed him, the detective said.

He also alleged that Harris told police he couldn't reach anyone on his telephone, but phone records show that Harris made three calls after he discovered his son's body, and one between him and his employer lasted six minutes, Stoddard said.

However, witness Leonard Madden offered a different version of what happened. Madden and an acquaintance were leaving a restaurant when they noticed a commotion and approached within 3 or 4 feet of a clearly distraught Harris.