The day after gunshots rang out on Purdue University's campus, police are trying to determine why Cody Cousins, 23, shot and killed Andrew Boldt, 21.

According to the Associated Press, Cousins, a student, entered the school's engineering building around noon and apparently targeted Boldt, a teaching assistant. Police said they were not able to find any evidence of past troubles between the two and have yet to discover a motive behind the shooting.

No one else was injured, eyewitnesses said the shooting was intentional and Cousins surrendered to police when they arrived on the scene. The building was immediately placed in a lockdown and the campus went under a shelter in place order, but both were lifted by 2 p.m. Classes even resumed that day, except for the engineering building due to a precautionary police search.

"Violent crime, whenever and wherever it occurs, shocks our conscience and incites our rage. When it happens in our home, to a family member - and as a Boilermaker Andrew Boldt was family to us - those emotions are more powerful still," Purdue president Mitch Daniels, who immediately returned from a university trip to Colombia, said in a statement at a campus vigil held Tuesday night.

Cousins and Boldt were teacher's assistants, according to the Los Angeles Times, and both were electrical engineering students. They can be connected through professors who teach various classes in the department, but still, no motive for murder is immediately present.

"Andrew Boldt was a young man who had the potential to make the world a better place. He was a phenomenal young man," Jean Morrell, Boldt's high school calculus teacher, told the AP. "He had a great mind but he also had a great heart. I'm just sad he won't get an opportunity to realize his dreams, to make his contribution to the world."

In a statement obtained by the AP, the young man's family was thankful for expressions of prayer and support in a difficult time. They also asked for privacy while they grieve their loss, adding there will be future opportunities for public prayer gatherings.

Cousins is being held without bond at the Tippecanoe County Jail on preliminary murder charges. He was uncooperative when first taken into custody and there is no indication that has changed.