By Carey Codd

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MIAMI (CBSMiami) — Drug test results have revealed that the Florida State University student accused of killing a couple and biting off part of the man’s face was not under the effects of any hallucinogenic substances.

A grand jury indicted Austin Harrouff, 19, on two counts of first degree murder, as well as attempted murder, in the August 15th attack on John Stevens, 59, and his wife, Michelle Mishcon, outside their Tequesta home.

Martin County deputies say they found the former high school football player and wrestler in his underwear, making animal noises and biting Stevens’ face as he pinned him to the driveway.

Harrouff also reportedly stabbed a neighbor, 47-year-old Jeff Fisher, who tried to help the couple.

But what prompted the attack?

Investigators, at the time, believed it possible that Harrouff was under the influence of some kind of drug like cocaine, or flakka, the notorious street drug known to cause violent outbursts.

However, other than marijuana and alcohol, no other chemical substance was found in his system.

Prosecutors released the gruesome photos of the crime scene Wednesday, including images of Harrouff in custody after his struggle with deputies. Police said he continued to attack Stevens despite being tased.

One of the crime reports said Harrouff was spitting out hair and flesh, begging for officers to kill him, saying that he “deserved to die.”

In the material released on Wednesday, we’re also hearing from some of the emergency crews who responded to try and help the victims. One of them, James Lee, an EMT, called Harrouff the devil.

“Bent down, quickly assessed the, uh, seemed to me like the devil, to be honest with you, whoever they had cuffed, briefly assessed him to see what was going on,” Lee told a Martin County Detective.

Lee said Harrouff said a few things at the crime scene.

“He was coming up saying, ‘F America. Just kill me,'” Lee said.

The documents released contain a police interview with Harrouff’s mother and sister after the crime. Harrouff’s mother, Mina, said her son was acting strangely that day and she played an audio recording of Harrouff for police.

“I become like almost immortal,” Austin Harrouff said on the recording. “I have to die one day.”

Harrouff’s sister said her brother had recently spoken about having super powers and that he struggled with insomnia. She said on the day of the killings his behavior was bizarre.

“He was talking about being immortal, running lights, being in front of cars, testing his powers, being half an animal,” Haley Harrouff said.

And some might argue on that night, he was.

Harrouff’s attorney and his family believe the teenager suffers from mental illness.