Austin Harrouff was not on flakka when he allegedly killed a Florida couple and tried to eat one victim's face, toxicology results reveal

A long-awaited toxicology report shows Austin Harrouff was not, as authorities openly speculated at the time, on flakka or bath salts when he allegedly killed a Florida couple at their home and tried to eat one of the victim’s faces, PEOPLE confirms.

Martin County Sheriff William Snyder initially told reporters Harrouff could “absolutely” have been on the synthetic drug flakka when he allegedly killed John Stevens and Michelle Mishcon in the garage of their Tequesta, Florida, home on Aug. 15.

“It absolutely could be a flakka case,” Snyder said soon after the killings, fueling widespread media attention.

However, toxicology results obtained by PEOPLE list no detection of the synthetic drug — a psychoactive stimulant that has been linked to bizarre behavior and drug overdoses — or bath salts in Harrouff’s system.

His attorney, Nellie King, said that the only drugs found in Harrouff’s system at the time, besides traces of marijuana components, were “medically introduced” during his weeks-long hospital stay after the gruesome attack, according to the Miami Herald.

Credit: Michelle Mischon and John Stevens

“Austin is struggling with severe mental illness, and the judicial process will bear all of this out in due time,” King said in a statement to PEOPLE.

She said Harrouff had been behaving strangely in the weeks before the attack — apparent symptoms of mental illness. According to King, Harrouff’s mother called police hours before the deaths of Mishcon and Stevens to report her son saying he had “superpowers” and was immortal.

“This is a cautionary tale for why law enforcement should endeavor to conduct complete investigations reliant on evidence, like toxicology reports, instead of speculation with no basis in fact,” King said in her statement. “We know this information will be of no comfort to the victims’ families and friends, but, as painful as this process is, it is critical for everyone involved to examine the facts and avoid jumping to conclusions,” King said.

Investigators allege a violent scene that August night, ending in the death of a much-loved couple.

“F—- kill me, f—- kill me! Shoot me now! I deserve to die!” Harrouff told Martin County sheriff’s deputies after they pulled him off of Stevens’ lifeless body in August, according to documents previously obtained by PEOPLE.

The deputies said they allegedly heard Harrouff say, “Help me, I ate something bad,”WPTV and CBS12 reported, citing additional new court documents.

When asked what he ate, Harrouff allegedly told officers, “Humans,” according to WPTV.

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Harrouff was charged on Oct. 3 with two counts of murder along with attempted murder, resisting an officer without violence and burglary of a dwelling while armed in the attack. He remains in custody, though it is unclear if he has entered a plea.

Harrouff initially tested negative for common street drugs such as heroin, cocaine, and marijuana.

A former defense attorney for the teen said in October that the attack was the result of an “onset of mental illness.” And Harrouff’s father, Wade Harrouff, previously told the Palm Beach Post that his son’s actions were not flakka-induced.

“The weird behavior is coming from schizophrenia in my family,” he said.

King said that Harrouff’s family noticed the teen had been “exhibiting signs of a mental health disorder weeks before the incident,” according to TC Palm.

King did not immediately respond to a request for comment from PEOPLE.