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TEQUESTA (CBSMiami/AP) — A Florida State University student accused of killing a couple and biting the dead man’s face remains hospitalized but is now conscious with guards by his side.

Austin Harrouff, 19, is unable to speak due to a breathing tube, according to the Martin County Sheriff’s Office. His life-threatening condition was upgraded to “stable” on Wednesday.

Deputies had not formally charged Harrouff with any crimes but the sheriff’s office says they are working with the State Attorney’s Office to determine the charges.

As for the victims of the gruesome attack, a small memorial now sits in front of their home. Neighbors have left flowers and are trying to make sense of what they called a horror show in the Jupiter neighborhood.

“I don’t understand it at all. It is absolutely senseless. It is beyond comprehension,” said neighbor James Dorsay.

“It’s kind of scary. This couple was doing nothing and they were attacked,” said neighbor Katie Ferguson.

Harrouff is accused of killing Michelle Mishcon, 53, and her husband, 59-year-old John Stevens, Monday night and seriously injuring a neighbor who tried to intervene.

Autopsy results show Mischcon died from blunt force trauma injuries and Stevens died from multiple injuries.

Meantime, detectives are trying to find out what prompted Harrouff to attack the couple.

Detectives said Wednesday they served a search warrant for additional testing of his blood, hair and DNA. It’s meant to help them get a more in-depth look of what was in his system. The tests have been sent to Florida Department of Law Enforcement (FDLE). The results are expected to come back within 1 to 3 weeks.

Harrouff reportedly tested negative for a number of drugs, including methamphetamine. Results for substances known to cause excited delirium — such a flakka and bath salts — are pending. Synder noted that Harrouff didn’t have the raised body temperature often associated with flakka use.

Martin County Sheriff William Synder said Harrouff – who has no criminal history and liked to sing and talk about bodybuilding on his YouTube channel – was eating with his parents earlier Monday evening when he got into an argument with his father – prompting him to leave.

Harouff’s mother called police three hours after he stormed out of the restaurant. The mother told police he had been acting strangely for a week and claimed he had superpowers. She said he had no history of mental illness and was not a heavy drug user.

John Stevens’ son, John Stevens IV, said he is heartbroken over the loss.

He said he and his wife recently had a child and his father was going to meet his granddaughter next month.

This son – and former Marine – believes there is something wrong with Harrouff.

“Obviously the kid was violent, repressed, entitled and upset and wanted to hurt somebody and now he’s hurt a bunch of people,” he said.

Neighbors said the Stevens were nice, quiet people. They were known to sit in the garage of their home with the door open. Snyder said that is where the initial attack took place.

When deputies arrived they reportedly found Harrouff on top of Stevens in the driveway, biting at his face and making animal noises.

It took several deputies and a K-9 to subdue Harrouff and take him into custody.

Mishcon’s body was found in the garage.

The sheriff said there is no connection between the suspect and the victims and happened seemingly as a random act of violence.

“I think it was a random act of violence. I can’t understand why this possibly transpired, why this guy acted the way he did,” said Dorsay.

This is not the first time something like this has happened in South Florida.

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