Police on Wednesday declined to publicly identify the assailant, going so far as to avoid any mention of the suspect's gender, nor did they give any information about the four victims struck by gunfire - three fatally - or their connection to the university.
The surviving gunshot victim was listed in stable condition, according to Sheriff Kevin McMahill of the Las Vegas Metropolitan Police Department.
WATCH 5 PM NEWS CONFERENCE: Get the latest information regarding the — LVMPD (@LVMPD) #ActiveShooter incident on the campus of UNLV on Dec. 6, 2023.📲https://t.co/XEC4KOmVi3There will not be another briefing tonight. pic.twitter.com/2qdW8lNPizDecember 7, 2023
He said several other people suffered panic attacks during the pandemonium, and a number of officers were treated for minor injuries sustained during a search of the sprawling campus for any additional victims or suspects. None were found.
No mention was made of a possible motive for the violence, and police did not disclose the type of firearm used.
Vincent Perez, a professor at the school, known by its initials UNLV, told MSNBC by phone that he had heard a lot of gunfire before taking cover on campus.
"I would say just seven, eight shots, one after another, loud and very loud," he said.
"As soon as we heard that, we ran back inside and we realised this is a real shooting, and there's an active shooter on campus."
Official details of the incident remained sketchy.
After receiving a call reporting gunfire on campus at 11.45am, law enforcement "immediately engaged the suspect in a shootout," UNLV police chief Adam Garcia told reporters. He said the suspect was fatally shot by campus police.
McMahill said the shooting began on fourth floor of Beam Hall, a building that houses the university's business school, then moved to other floors before finally ending outside where the suspect was "neutralised."
Police said the university would remain closed at least through Friday.
The UNLV campus, just east of the Las Vegas Strip, has a student enrollment of some 25,000 undergraduates and 8,000 post-graduates and doctoral candidates.
The sheriff said many students he encountered appeared to have been badly shaken, recalling how people were likewise traumatised in the aftermath of a mass shooting in 2017, when a gunman opened fire from a high-rise hotel window onto a music festival below along the Las Vegas Strip.Â
Sixty people were killed and hundreds more were wounded in what still ranks as the deadliest mass shooting by a single gunman in US history.