Idaho Student Murder Suspect: 8 Key Revelations

The murder of four Idaho college students gripped national attention for weeks, partly for the grisly nature of the crime, partly because there no suspect had been identified as the investigation wore on. 

It turns out officials were tracking down 28-year-old Bryan Kohberger. They've charged him with the murders of Kaylee Goncalves, Madison Mogen, Xana Kernodle and Ethan Chapin, who were stabbed to death in their rooms in an off-campus house on Nov. 13. Officials don't believe he has any connection to the students, which made the prevailing question even more urgent—who is he? 

Read on to see eight key revelations authorities have made about Bryan Kohberger and the case from rural Idaho that continues to shock people coast to coast.

Surveillance video captured a white car driving past the house where the murders were committed four times, starting at 3:29 am and ending at 4:20 am, minutes before the students were stabbed to death in their rooms. Police narrowed down a list of 20,000 potential vehicles to determine that it was a 2015 Hyundai Elantra registered to Kohberger, a 28-year-old doctoral student in criminology at Washington State University, just across the border in Pullman, Washington. 

Kohberger was pursuing a doctorate in criminology at Washington State University in nearby Pullman, Washington. He had earned a bachelor's in psychology and master's degree in criminal justice at DeSales University in Center Valley, Pennsylvania. Some experts speculate that he might have been studying how to commit the perfect crime; others say that pursuit would be a waste of time as DNA technology makes the "perfect crime" impossible.

Investigators say that DNA evidence played a key role in identifying Kohberger as a suspect. In an affidavit, investigators said the killer left his DNA on a "leather knife sheath" found on a bed next to one of the victims. Kohberger drove from Washington to Pennsylvania with this father for the holidays. Agents analyzed trash from the family home, determining there was a strong likelihood that the elder Kohberger was the father of whoever left DNA on the knife sheath.

Rich Pasqua, an acquaintance of Kohberger's, said he was addicted to heroin in the years before the murders. "I got six years clean now," Pasqua told Fox News on Saturday. "I work in treatment and everything, but back then I was using. And so that's how I know for a fact he was using. I've got high with him a couple of times and used with him." Pasqua said he knew people who delivered drugs to Kohberger often.

"​​He seemed very comfortable around other people," classmate Benjamin Roberts told CBS News. He was very quick to offer his opinion and thoughts. And he was always participating fairly eagerly in classroom discussions."

Others disagree. "People are talking about how smart he supposedly is. And I just can't see how that could be true, because any student of forensic science or criminology would have to know that it's virtually impossible not to leave your DNA behind at a very violent, intimate crime scene like this," said genetic geneologist CeCe Moore.

As a teen, Kohlberger was overweight, "so he was bullied a lot," high school friend Casey Arntz told CBS News. But he lost nearly 100 pounds before his senior year. "He was a rail," said Arntz. "It was after that weight loss that a lot of people noticed a huge switch in him." He began bullying others, friends say, and using heroin. 

Kohberger had recently applied for an internship at the police department in Pullman, authorities said. As part of the application, he submitted an essay on his interest in helping rural police departments collect and analyze data.

At DeSales, he studied with Katherine Ramsland, a forensic psychologist whose books include The Mind of a Murderer and How to Catch a Killer. Authorities say during his studies, Kohberger posted a Reddit survey—sanctioned by the university—asking ex-cons about the crimes they committed. One question he asked: "Before making your move, how did you approach the victim or target?