LAS VEGAS >> The 67-year-old gunman who killed three faculty members and wounded a fourth in a roughly 10-minute rampage at the University of Nevada, Las Vegas, had a list of targets at the school and more than 150 rounds of ammunition, police said Thursday.

Clark County Sheriff Kevin McMahill identified the suspect, who was killed in a shootout with police, as Anthony Polito, a longtime business professor who was living in nearby Henderson, Nevada. The sheriff said at a news conference that investigators were still looking into a motive but noted that Polito had applied for several jobs at various colleges and universities in Nevada but was denied the job each time.

However, Roseman University of Health Sciences in Henderson said Polito had an adjunct faculty contract and taught two courses in the school’s Master of Business Administration program from October 2018 to June 2022. He left when the program was discontinued, said Jason Roth, a spokesperson for the school.

McMahill said targets on Polito’s list also included faculty members at East Carolina University in North Carolina, where Polito was a professor at the university’s business school from 2001 to 2017.

“None of the individuals on the target list became a victim,” McMahill said, adding that police have contacted everyone on the suspect’s list, except for one person who is on a flight.

Before the shooting, Polito also mailed 22 letters to university faculty members across the U.S., according to footage reviewed by detectives from a dashcam in Polito’s vehicle, McMahill said. At least one of the envelopes contained an unknown white powder substance, he said.

Terrified students and professors cowered in classrooms and offices as the gunman roamed the top three floors of UNLV’s five-story Lee Business School around lunchtime Wednesday.

Polito arrived at UNLV about 15 minutes before the shooting in a 2007 Lexus, McMahill said. He exited his car, placed items in his waistband and then entered the business school just after 11:30 a.m. The first reports of gunfire came about 15 minutes later, McMahill said.

The sheriff said the rampage ended around 11:55 a.m., when Polito left the business school and was confronted by police outside the building.

The suspect’s weapon, a 9 mm handgun, was purchased legally last year, McMahill said.

Police were still investigating how many rounds were fired during the attack. But the sheriff said that due to the sheer amount of ammunition in the gunman’s possession, he believed Polito may have been headed to the student union, which is next to the business school, when university police officers found him and he was killed in the shootout.

McMahill said the shooter brought 11 magazines with him to the campus, and police found nine of them on the shooter after he was killed.

It wasn’t immediately clear how many of the school’s 30,000 students were on campus at the time, but McMahill said students had been gathered outside the building and the student union to eat and play games. If police hadn’t killed the attacker, “it could have been countless additional lives taken,” he said.

UNLV President Keith E. Whitfield identified two of the victims who were killed as business school professors Patricia Navarro-Velez and Cha Jan “Jerry” Chang. Whitfield said the name of the third victim will be released after relatives have been notified of the death.

In a letter to students and staff, Whitfield said that the shooting “was the most difficult day in the history of our university.”

The wounded man, a 38-year-old visiting professor, was still hospitalized Thursday. McMahill said his condition had been “downgraded to life-threatening” from critical.

Navarro-Velez, 39, was an accounting professor who held a Ph.D. and was currently focused on research in cybersecurity disclosures and data analytics, according to the school’s website.

Chang, 64, was an associate professor in the business school’s Management, Entrepreneurship & Technology department and had been teaching at UNLV since 2001. He held degrees from Taiwan, Central Michigan University and Texas A&M University, according to his online resume. He earned a Ph.D. in management information systems from the University of Pittsburgh.

The attack at UNLV terrified a city that experienced the deadliest shooting in modern U.S. history in October 2017, when a gunman killed 60 people and wounded more than 400 after opening fire from the window of a high-rise suite at Mandalay Bay on the Las Vegas Strip, just miles from the UNLV campus.

Authorities on Thursday said Polito appeared to be struggling financially. When they arrived at his apartment Wednesday night to search the property, McMahill said, they found an eviction notice taped to his front door. Inside the apartment, detectives found a chair with an arrow pointing down to a document “similar to a last will and testament,” McMahill said, though the sheriff did not provide specifics on the contents of that document.

It wasn’t immediately clear how long Polito had been living in the Las Vegas area. He resigned from East Carolina University as a tenured associate professor, according to a statement Thursday from the university.

One of Polito’s former students at East Carolina, Paul Whittington, said Polito seemed obsessive over anonymous student reviews at the end of each semester.

Polito told Whittington’s class that he remembered the faces of students who gave him bad reviews and would express that he was sure who they were and where they sat, pointing at seats in the classroom, Whittington said.

“He always talked about the negative feedback he got,” said Whittington, now 33, who took Polito’s intro to operations management class in 2014. “He didn’t get a lot of it, but there would always be one student every semester, or at least one student every class, that would give a negative review. And he fixated on those.”

Classes at UNLV were canceled through Friday, and the Wrangler National Finals Rodeo canceled events that were scheduled Thursday night at the Thomas & Mack Center at UNLV.

Associated Press reporters Terry Tang in Phoenix; W.G. Ramirez in Las Vegas, Russ Bynum in Savannah, Georgia, Michael Balsamo in Washington and Robert Jablon in Los Angeles contributed to this report.