Nineteen-year-old Austin Harrouff seemed to have it all: he was handsome, a good student and a former popular high school football player. But on the night of August 15, 2016 police claim the all-American FSU college football star transformed into a brutal, superhuman killer.

After abruptly leaving dinner at a restaurant with his family, police claim Harrouff walked 2.8 miles to the home of 59-year-old John Stevens and his wife, Michelle Mischon, and stabbed the couple numerous times and violently bit the face and abdomen of one of his victims, before stabbing a neighbor who was trying to save the couple’s lives. It allegedly took a police dog and four deputies to pry the teen, who was reportedly growling like an animal, off the victims.

WATCH: First Thing Police Reportedly Told Father of Teen Who Allegedly Committed Gruesome Murders: ‘He’s Killed Two People And Eaten Them’ 

Harrouff has been dubbed the “face eating” frat boy by some media, however his father, Dr. Wade Harrouff, says his son is not a monster.

Speaking out for the first time in a sit-down interview with Dr. Phil airing Wednesday, Dr. Harrouff claims that his son only began exhibiting bizarre behavior approximately two weeks before the murders occurred.

“I knew the whole week he was acting weird. I just said, ‘Put that up,’ and he snapped out of it, and he started being friendly again,” Dr. Harrouff says. “I kept on thinking I could lick it. Having fun with it, we could lick this thing. It’s just a temporary thing.”

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However, he says the behavior continued.

In the video above, Dr. Harrourff describes what he calls his son’s “abnormal” behavior the evening the murders occurred, including allegedly eating a large amount of Wesson oil and disappearing from a family dinner.

WATCH: What Does Father Of Frat Boy Dubbed ‘The Cannibal Killer’ Think Caused His Son’s Alleged Behavior?

On Wednesday’s episode, Dr. Harrouff recalls learning his son may have committed this horrific crime and what he believes may have caused the teen’s behavior. Check here to see where you can watch.