The man accused of fatally shooting a professor on the University of Arizona campus in Tucson this week is a former student who had been banned from campus due to harassment complaints, according to court filings.
The suspect, Murad Dervish, 46, was taken into custody on Wednesday hours after the shooting inside the campus' John W Harshbarger building, police said.
He faces charges including first-degree murder and aggravated assault, according to the interim complaint filed in Pima County Superior Court.
Dervish "has been the subject of several reports of harassment and threats to staff members working at Harshbarger," the complaint stated.
He was expelled from the school in February and is barred from being on University of Arizona property, according to the complaint. An email with his photograph was sent to staff members in February "with instructions to call 911 if he were to return to the building," the complaint stated.
Dervish is being held without bond at the Pima County jail, Pima County Sheriff Department's records show. It is unclear if he has an attorney.
Police said the suspect used a handgun in the deadly attack.
Approximately 11 shell casings were found at the murder scene, according to the complaint. The victim was struck and killed by approximately four bullets, according to the complaint. Another person in the office was stuck by a bullet fragment or spalling and was treated and released at the scene, according to the complaint.
Police responded around 2 p.m. local time after someone at the Harshbarger building reported that a former student was in the building who wasn't allowed to be there, University of Arizona Police Chief Paula Balafas said at a news conference Wednesday. The caller wanted the person escorted out by police, she said.
Police were en route when the shooting occurred inside the building, Balafas said. The victim was transported to a local hospital, where he was pronounced dead, she said.
The suspect fled the campus and was arrested shortly after 5 p.m. following a traffic stop by the state’s Department of Public Safety near the town of Gila Bend, Balafas said.
A loaded 9mm handgun was found in his car, and the ammunition was consistent with the shell casings found at the murder scene, according to the complaint.
Prior to questioning, Dervish allegedly told police, "I hope he's okay, probably wishful thinking," and "I just felt so disrespected by that whole department," according to the complaint.
The victim was identified Thursday as professor Thomas Meixner, department head of the Department of Hydrology and Atmospheric Sciences, said university president Robert Robbins.
"This incident is a deep shock to our community, and it is a tragedy. I have no words that can undo it, but I grieve with you for the loss, and I am pained especially for Tom’s family members, colleagues and students," Robbins said.
The University of Arizona College of Science described Meixner as a "wonderful and kind person, whose larger-than-life approach to being and doing inspired those around him and elevated the community."
Meixner is survived by his wife, Kathleen Cotter Meixner, and two sons.
The university is holding a candlelight vigil Friday in his honor.
ABC News' Marilyn Heck and Teddy Grant contributed to this report.