Suspect in deadly face-biting attack identified as 19-year-old Florida university student

A man has been arrested after a gruesome and random murder of an older Florida couple outside their home north of Palm Beach on Monday.

The Martin County Sheriff’s Office said a 19-year-old Austin Harrouff was possibly high on hallucinogenic drugs when he fatally attacked, beat, and stabbed Michelle Mishcon, 53, and John Stevens, 59, while they sat inside their garage.

Martin County Sheriff William Snyder said Tuesday that deputies captured the Florida State University student as he was biting the dead man’s face in their driveway in Tequesta, an affluent coastal community.

Authorities also said a neighbour who tried to pull the suspect off the victim was also stabbed.

WATCH: Victim who survived deadly Florida face-biting attack recovering in same hospital as suspect

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Snyder described Harrouff as delirious and being “abnormally strong” when police responded to the incident. Officers struggled to get Harrouff off the male victim even with the use of a Taser. A K-9 unit was called in to assist in apprehending Harrouff, but even a bite from a service dog failed to subdue him.

“Someone not feeling pain, somebody not responding to a dog biting, not responding to repeated stuns from a Taser, taking 3 or 4 deputies, an officer, and a dog to get him off, that’s somebody with a lot more strength than you would normally encounter,” said Snyder.

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Snyder said officers declined to use guns out of fear of wounding the victim.

“The angles were extremely dangerous and had there been a gunshot it could have hit the victim,” he said.

Police eventually removed Harrouff from the victim and was taken to a local hospital where he was sedated.

Snyder, who called the incident “perplexing,” confirmed Harrouff was tested for methamphetamine, cocaine, heroin and other common drugs, but none were found in his system.

Police hope to conduct more tests to see if the student was under the influence of flakka or bath salts. Bath salts have been blamed on a series of bizarre crimes committed in south Florida.

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Snyder confirmed Stevens and Mishon were both declared deceased at the scene.

Snyder said the neighbour suffered “substantial trauma” and underwent surgery at a local hospital.

Police said Harrouf has no criminal record.

-With Files from the Associated Press