(NEW YORK) -- As pictures of Bryan Kohberger, the suspect in the murders of four University of Idaho students, were published in the media, Hayden Stinchfield thought he looked familiar.
The man in the mug shot looked just like a teaching assistant for Stinchfield's criminal law class last semester at Washington State University, he told Good Morning America.
"Initially, I didn't believe it," Stinchfield said. "Like, I had to go double check, you know, with the names and everything, because I saw Bryan when I saw the picture -- and I was, like, all right, that looks like my T.A."
Stinchfield checked his email. He searched the school directory. The names matched. His teaching assistant was the suspect.
"Such a shocking realization, you know," Stinchfield said.
Kohberger, 28, who is expected to appear in court in Pennsylvania on Tuesday, is a Ph.D. graduate student in criminal justice, according to the university.
Stinchfield, an undergraduate studying criminal justice, said he had a handful of personal interactions with Kohberger. The assistant also offered notes on his papers.
He said he didn't remember Kohberger discussing the murders, which the class's professor only briefly brought up. But he said he remembered Kohberger standing up to address the class fewer times toward the end of the semester.
Stinchfield said he thought at the time that Kohberger's lack of engagement might have been because students had argued over their grades with him earlier in the semester.
"But, you know, maybe there was more to that now," he said.
He told GMA that he didn't notice any "huge" changes in Kohberger's classroom behavior around the time of the murders.
But, Stinchfield said, Kohberger did look "a little bit more disheveled" than usual during finals.
"He had some stubble coming on. His hair was a little, you know, messed up, or whatever -- nothing crazy," Stinchfield said. "But enough that I remember seeing him and thinking, 'Oh man, you know, finals much be really getting to him,' or something like that."