(NewsNation) — After weeks of investigation, detectives arrested 28-year-old Bryan Kohberger on a warrant for the murders of college students Kaylee Goncalves, Madison Mogen, Xana Kernodle and Ethan Chapin.

Kohberger, a criminology student at Washington State University, is now one of America’s most notorious inmates.

He grew up in Pennsylvania and attended high school in the area near the Poconos mountains. A former friend told NewsNation’s Chris Cuomo that Kohberger was bullied as a teenager.

“He was always good to me. Over the years that changed. Going into his senior year, he lost a lot of weight. And I heard that he might have become a bully,” Casey Arntz said.

Arntz also claims Kohberger had a drug problem, even using her to try to get drugs.

“He did use me and I didn’t know he was using me to get heroin until a couple days afterwards,” she said.

An old running partner of Kohberger said he was shocked when he heard about the arrests.

“I looked at the picture and I couldn’t believe who it was. It was Bryan Kohberger. I would text him and be like hey do you want to go for a run? We’d go for like 6-7 mile runs at night,” Schyler Jacobson said.

Kohberger got his bachelor’s degree at DeSales University in 2020, followed by a master’s degree from the school’s criminal justice program. A spokeswoman from the school said they are absolutely distraught by what is happening.

At DeSales, Kohberger was taught by a world-renowned forensic psychology professor, Dr. Katherine Ramsland.

A professor and consultant, Ramsland is most famous for her in-depth interviews with Dennis Rader, known as the BTK Killer. Rader confessed to stalking and killing at least 10 people in the 1970s and 1980s, then taunting the police and media before he was eventually arrested in 2005.

“He asked me to solve a series of codes and I was willing to pass the test,” Ramsland told NewsNation, on how she got the interviews.

Ramsland wrote Rader’s autobiography. Last year, she sat down with NewsNation’s Marni Hughes to discuss why she gave the serial killer a platform.

“I did this because I wanted to benefit law enforcement, criminal justice and psychology. We want to learn about the early red flags and the life of someone like this who doesn’t have the typically serial killer background,” she said.

Ramsland told NewsNation she is not making any comments about Kohberger or the Idaho case at this time.

However, Rader’s daughter Kerri Rawson told NewsNation the connection between Kohberger and Ramsland concerned her.

“My first reaction was my stomach turned,” Rawson said. “Knowing how personally connected Ramsland is to my father I would not be surprised if Kohberger tried to write my father.”

After getting his master’s degree at DeSales, he moved to Pullman, Washington and became a Ph.D candidate and teaching assistant at WSU, just across the border from Idaho. He lived in an on-campus apartment for graduate students.

The affidavit for Kohberger’s arrest claims he applied for an internship with the Pullman Police Department in 2022, saying in his essay he was interested in “assisting rural law enforcement agencies with how to better collect and analyze technological data in public safety operations.”

He also posted a survey on Reddit asking for volunteers for a research study where he was studying the criminal mind, according to the probable cause affidavit filed ahead of his arrest. He wanted to know about the emotional and psychological considerations of people who had been convicted of crimes.

The survey included questions about why the person chose their specific victim, what the first move they made was and how they left the scene of the crime.

Benjamin Roberts, a classmate of Kohberger’s at WSU recalled Kohberger being the type of student who wanted to make sure everyone knew how smart he was.

“He had to make absolutely sure you understood that he was smart,” Roberts said.

He said Kohberger’s demeanor changed before winter break.

“I did notice that he became a little more chattier, he became a little more animated. Mostly what I noticed though is he was always showing up a little late, he was always showing up with a cup of coffee in hand, he seemed like he was more exhausted,” Roberts said.

Kohberger hasn’t entered his plea yet, though he has been extradited from Pennsylvania to Idaho, where he is being held in the Latah County jail.

Kaylee Goncalves’ father spoke about seeing the man accused of killing his daughter for the first time.

“I expected him to be a bigger monster and more intimidating. I mean I’m like this is the guy?” Steve Goncalves said.

The sheriff’s office in Latah County said the county is trying to accommodate Kohberger’s vegan diet while he is being detained.

A reporter who interviewed Kohberger’s aunt told NewsNation’s Ashleigh Banfield about Kohberger’s so-called “food fetish.”

“She said it went behind being vegan, he required his aunt and uncle to buy brand new pots and pans for him to eat out of because he refused to eat anything that ever had meat cooked in it. And she said it seemed to be an OCD situation,” sid Dana Kennedy, a reporter with the New York Post.

In a statement, Kohberger’s family said they continue to support him.

“We will continue to let the legal process unfold and as a family we will love and support our son and brother. We have fully cooperated with law enforcement agencies in an attempt to seek the truth and promote his presumption of innocence rather than judge unknown facts and make erroneous assumptions,” the statement read.

For Steve Goncalves, there is a clear vision of what justice for Kaylee looks like.

“Justice doesn’t have a room where you read books and you can go to school and you can have 3 meals and you can have your vegan diet. To me that’s not justice. Justice is when you leave the planet and the whole world is able to rejoice and be glad that you’re not there,” he said.