In a weird and horrific attack, a Florida State student stabbed a couple and was caught biting the male victim’s face.

Time reports.

College Student Tries to Bite Man’s Face Off After Stabbing Him to Death, Police Say

A 19-year-old college student in Florida grunted and growled as he allegedly attacked a married couple, killing them outside their home in an “inexplicable” assault that may have been sparked by drug use, authorities said.

Austin Harrouff was hovering over one of his victims, John Stevens, and biting the 59-year-old’s face Monday night before deputies arrived and subdued him, Martin County Sheriff William Snyder said Tuesday.

Harrouff, a Florida State University student with good grades and no criminal record, was “exhibiting abnormal levels of strength” and did not respond to being stunned by a deputy’s Taser, being bitten by a police dog or tackled by at least three law enforcement officers. “Nothing was working. They were using all the force they were able to muster physically,” Snyder told reporters at a news conference.

Stevens died on his driveway while his 53-year-old wife Michelle Mishcon was found dead inside the garage. Both were stabbed multiple times and sustained “massive trauma” to their bodies. “There was an enormous amount of violence inside that garage,” Snyder said.

The victims did not know Harrouff, according to the sheriff, who added that the attack was “completely unprovoked and random.”

“It’s inexplicable,” Snyder said. “One of the first things we try to do at a crime scene is try to understand the motive of the offender, because it is the motive of the offender that gets us going in the right direction. In this case, we can’t establish a motive. It’s ‘I don’t know.’”