The case of the Martin County teenager who attacked a couple at random, stabbed them to death, then started to eat away at the face of one of his victims, shocked the nation.
The father of Austin Harrouff reveals new details of what happened hours before police say his son murdered John Stevens and Michelle Mishcon-Stevens.
RELATED: More coverage of the case
Dr. Wade Harrouff broke down on the "Dr. Phil Show" as he apologized to the families of his victims.
He revealed that his son's mental health had noticeably declined in the two weeks leading up to the attack.
In the interview, Dr. Harrouff says that he was sitting down with his girlfriend and Austin for dinner at the Duffy's on Indiantown Road. Austin excused himself to go to the bathroom - and never came back.
Later in the evening, Dr. Harrouff says he received a strange call from his former wife.
Dr. Phil: Did she notice anything unusual about him when he got to the house?.
Dr. Harrouff: Yes.
Dr. Phil: What was it?
Dr. Harrouff: He grabbed a bottle of Wesson oil and was going to drink it. She stopped him and he poured a bowl, put Parmesan cheese in it and ate that. Very abnormal.
Austin's mother brought him back to the restaurant, where Dr. Harrouff confronted him.
Soon, Austin took off again.
It was the last time Dr. Harrouff saw his son that night.
In the interview, he says his son's throat was burned by chemicals he ingested.
In the latest update from Martin County Sheriff's Office, they told NewsChannel 5 Austin remains unable to speak.
Detectives will continue to monitor him and attempt to speak to him at first possible opportunity.
He remains in critical but stable condition.