CHICAGO (CBS) — Family and friends were remembering a slain Loyola University student Tuesday morning, four days after he was shot and killed during a robbery near campus.

Mutahir Rauf, 23, graduated from Northwestern University with a double bachelor’s degree in psychology and science, and then enrolled at Loyola for a graduate-level pre-med program when he decided he wanted to become a doctor.

Rauf and his brother, Mokaram, were walking in an alley near Albion and Lakewood when two men approached them, showed a gun, and demanded money. Rauf thought the gun was a fake and tried to grab it. That is when the suspect fired, shooting Rauf in the head and chest. His brother was not injured.

An interfaith memorial service was held Tuesday morning at the Mundelein Center on Loyola’s Rogers Park campus.

“We seek peace, not vengeance; understanding, not bigotry. We see this brutal act as being symptomatic of a greater epidemic of poverty and violence pervading Chicago,” Mokaram said Tuesday. “It’s not about playing the blame game, it’s not about catching the perpetrators and letting that be the only thing, it’s about understanding why this happened, and how do we prevent other families from having their Mutahirs taken away from them.”

Mokaram said, silly as it sounds, his best memories of Mutahir were the times Mokaram would return from a trip, and his younger brother would be ready to show how strong he was, and carry his older brother’s luggage, and give him a big hug.

Their parents traveled to Chicago from Pakistan to honor their son, and bring his body back to Asia for burial.

Mokaram said Mutahir was motivated by a desire to help people.

“He specifically decided to pursue medicine, largely because he wanted to matter, in the sense of providing for humanity. He was largely inspired by some of his work in outreach activities that he did in seyboo Philippine,s where he worked with underprivileged communities, and was inspired by the various hardships that they faced,” Mokaram said.

Loved ones have set up a makeshift memorial at the scene where Mutahir was killed.

The shooting was under investigation, but no one was in custody as of late Tuesday morning.

The robbers are believed to be in their late teens or early-20s.