The man accused of slaying four University of Idaho students in their beds was a “creep” at high school who was bullied by girls, former acquaintances claim.

Bryan Kohberger, 28, was arrested early on Friday morning at his parents house in Pennsylvania, more than 4000km across the country from the site of the killings in the US.

The bodies of roommates Kaylee Goncalves, 21, Madison Mogen, 21 and Xana Kernodle, 20 as well as Kernodle’s boyfriend Ethan Chapin, 20 — were found on November 13 at their rented home off campus in the town of Moscow, Idaho, several hours after investigators believe they died.

Kohberger is currently a PhD student and teaching assistant in the Department of Criminal Justice and Criminology at Washington State University.

But those who knew Kohberger in high school have come forward saying he was an overweight “outcast” who was bullied but that he transformed himself in his senior year - to the surprise of his peers.

“I remember seeing him and thinking it was a new student,” Dominique Clark, who was at elementary and high school with Kohberger, told The New York Post.

“He was so heavy and he lost so much weight, he almost looked sickly, or like it was an obsession.”

Kaylee Goncalves, Madison Mogen, Ethan Chapin and Xana Kernodle were stabbed to death in their beds. Photo / Facebook

Clark said he lost about 36kg while the pair attended Pleasant Valley High School in Brodheadsville.

“Around the same time, he became more aggressive, and I think he became more of an outcast at that point. He became more withdrawn.”

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She also told The Post that Kohberger was a bit odd and socially awkward, especially around girls.

“If he liked or was interested in a girl and she wasn’t, he didn’t understand why or just didn’t accept her saying no and move on and so he would have been labelled as a creep or something along those lines,” said Clark.

“He hung out with the people who were outcasts together. He tried to hang out with people who were smart,” she continued. “He just didn’t really fit in with anybody.”

Bryan Kohberger is being held for extradition in a homicide investigation in the killings of four University of Idaho students. Photo / Monroe County Correctional Facility via AP

Casey Arntz, who was friends with Kohberger, has posted a series of videos to TikTok claiming he had “anger issues” and was a “heavy heroin user back in high school”.

Another former classmate, at Northampton Community College, told Fox News that Kohberger was still struggling with drug addiction into his college years, claiming the pair would talk for hours about his weight and drug battles.

Arntz said that the last time she saw him, a few years ago, he told her he was now clean.

“He seemed like he was better. Obviously that wasn’t true,” Arntz said.

“A lot of the kids that I was in school with are saying that, you know, Bryan was bullied as a kid, which I can believe cos he was an overweight kid. But then he lost all the weight. And some people are saying that he accepted apologies from other people. Other people are saying that he then bullied them back. I don’t know, there’s a lot of speculation.”

However, she added, “In the time that I did know Bryan, he was nice to me”.

“He would message me, he would start the conversations, he would compliment me, he would wanna invite me to hang out with him.”

A Moscow police officer stands guard in his vehicle at the home where the four University of Idaho students were found dead. Photo / AP

Another classmate at Pleasant Valley High School told Fox News that Kohberger was shy and was bullied by girls who mocked him and threw objects.

“It was bad,” Sarah Healey said. “There was definitely something off about him, like we couldn’t tell exactly what it was.”

She said Kohberger randomly approached her one day, asking to spend time together when they didn’t even know one another.

“I remember one time when I was walking in the hallway, and he stopped me and was like, ‘Do you want to hang out?’ It was just weird.”

She said she overheard some girls telling Kohberger to “go away, creep” or saying “I don’t want to hang out with you”.

“I honestly think that’s what led up to this, because he didn’t get the proper help, and it was mainly females that bullied him.”

Federal and state investigators are now combing through Kohberger’s background, financial records and electronic communications to identify a motive and build their case, a law enforcement official said.

Autopsies showed all four students were likely asleep when they were stabbed multiple times, but there was no sign of sexual assault, police said.

Chief public defender Jason LaBar said his client plans to tell a Pennsylvania judge on Tuesday that he will waive his extradition hearing so he can be taken to Idaho to face murder charges over the killings quickly, as he is eager to be exonerated.