The defense council for Ryan and Heather Sanders, two parents charged with injuring three of their children, called their first witness in court Friday.

Dr. Diana Lynn Barnes, a psychotherapist from California, took the stand Friday, testifying that Ryan Sanders suffers from post-traumatic stress disorder and depression brought on by childhood abuse.

She also added that Heather Sanders was suffering from postpartum depression after giving birth to her fourth child while the couple was living out of a vehicle near Bob Hall Pier, which could have played a role in why Heather did not seek any medical attention for fear of having her baby taken away.

Dr. Barnes advised the jurors that both parents felt that they did not intentionally harm their children.

"Ryan, from the review of the records, from talking with him, really believed that he was doing the best possible thing that he could for his children under unbelievably trying circumstances," Barnes said. "They were trying to survive."

The trial is expected to go on for another two or three weekends before there is a verdict.