Thursday morning, the defense called experts to debunk some of the police witnesses called earlier by the prosecution in the Ross Harris hot car murder trial.

The defense called a memory expert to the stand Thursday morning to testify on whether or not Ross could have forgotten his son in the backseat.

Dr. Gene Brewer, with Arizona State University’s psychology department, studies human memory and human attention control.

The defense asked him if it was possible for Ross to have forgotten 22-month-old Cooper back in June 2014.

He tells the court that Ross could have experienced fatigue based off of the emails that he sent the day before work—continuing that this could be factor as to why he forgot.

When the prosecution cross examines Brewer, he testifies that most cases when a parent forgets a child, the child is out of view from the driver—but not familiar with any case in which a parent drove a short distance and forgot their child. He agreed with the prosecution that some sort of distraction played a part in what happened.

On Wednesday, defense attorneys called friends and co-workers of Harris to continue to bolster their position posing him as an upright and solid family man, as opposed to the more secretive man living a double life that prosecutors want the jury to see. They insist that Harris hid a darker second life as a sex-addicted man engaged in risky behavior, and that this risky behavior placed his young son's life at risk.

The prosecution's arguments suggested that the defense witnesses did not know and did not recognize the signs of Harris' second life, so they would not be aware of what to look for.

Harris faces a number of charges, including malice murder and felony murder in the death of his young son, Cooper back in June 2014. The 22-month-old was found dead in the back seat of father’s SUV in a suburban Atlanta office park. The defense claims that the death of Cooper was a tragic accident.

PHOTOS | Ross Harris Hot Car Death Trial - Day 20

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