TEMPE, Ariz. -- Arizona State University police said they still have no idea why a graduate student pulled out a gun and shot himself in the head just seconds after arriving for an appointment with a professor in the instructor's office.

Tempe resident David Solnick, 59, was talking to Prof. Mookesh Patel when he pulled out a gun and committed suicide on ASU's main campus in Tempe on Monday.

Solnick was dead when paramedics arrived at the scene.

Things appeared back to normal on Tuesday at ASU's Design College but a small cup of flowers and an outreach effort by a campus ministry offered subtle reminders that something tragic had happened there.

"We just wanted to put some signs out today and open the place up and really make sure we were visible and offer a space a spiritual presence," said Rev. Rob Rynders of Campus Methodist Ministry.

The shooting has campus police asking hard questions.

"We don't know why he chose the professor," said Cmdr. Jim Hardina of ASU police. "Why he chose the office. We really don't know those specifics and I don't know if we'll ever know that."

Police said Solnick and Patel did not appear to have a personal relationship, only that of a student and professor.

Police said a search of Solnick's home offered few clues -- no note and no indication he was having trouble in the graduate program.

ASU spokeswoman Julie Newberg said counselors were made available to help students, faculty and staff cope with the incident.

Patel, who was not on campus Tuesday, has been talking to counselors and is still in shock, his wife said.

According to the school's Web site, Patel meets with students by appointment only, and they must sign up at least 72 hours in advance.

School Uses Emergency Text-Messaging System

An alert went out on the school's emergency text-messaging system about 30 minutes after the event.

"Arizona State University is deeply saddened to report that a male graduate student committed suicide at the Architecture South building on the Tempe campus this morning," Newberg said in the alert.

Design student Ben Tieni, who was in the building at the time of the shooting, said the school's response was "really quick."

"I feel there's not a lot of places (where) I feel safer than at the school," Tieni said. He also said the design students were a tightly knit group.

Students and faculty who want to sign up for the free alert can visit www.asu.edu and click on the ASU alert logo.