Some students who know Kevin Boyar said he was mild-mannered and sweet.
But others said he was irritable and had a bad temper.
Kaethe Richter, who went to high school with Boyar, said he was a "very positive person" who enjoyed participating in sports.
Richter said he was an athletic trainer at Eldorado High School, was on the swim team and enjoyed spending time with his mother.
But Boyar's former roommate, Nick Arugelles, said he seemed to have a problem controlling his anger.
"He was definitely crazy," Arugelles said. "One time he got so angry - I guess somebody ate his food out of the freezer - he got so angry he went and got a lock box and put it in the freezer, and he was the only one with the key."
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Arugelles said Boyar would get violent whenever he lost in a video game.
"He liked to play video games - like shoot-'em video games. He would get really, really crazy angry when he'd lose," he said. "He would throw the control around and yell and stuff."
Richter said her friend dated Boyar during her freshman year of high school. He was sweet, she said.
"They only dated for a little while," she said. "She was going to go to the dance with him, and then I guess his mom got kind of creepy because his mom was really involved in his life."
Boyar's mother, Peggy, declined to comment.
Arguelles said he lived with Boyar for one year until an ugly fight forced him to move into another dorm.
"There was a big argument between two of the guys," he said. "Kevin was involved in that. It was their argument, but we ended up moving out anyway. I just didn't want to get involved in it."
Resident adviser Ivan Miller said he didn't know Boyar well.
"I don't know if he stayed in his room, and I only met him and checked him in," he said. "He never really came to any of the programs."
Miller said Boyar's roommates have been forced to relocate now that the dorm is a crime scene.
"We gave them a lot of time just to pack all of their stuff," he said. "They definitely have everything they need, and they have us on call if they need to. If anything, we're happy to go in there and get something out of there."
Miller said this is the first time he has seen anything this serious happen in the dorms.
"I run into everything," he said. "I've been an RA for a couple of years. You just kind of take it as it goes. If it's something this big, then obviously that's someone we don't need in our dorms here trying to do anything dangerous."
