The fatal shooting of Charlie Kirk has put Utah Valley University (UVU) under scrutiny as security experts said the location of the stage for the outdoor event where the conservative commentator was targeted was particularly vulnerable, and questioned why no metal detectors were in place and bags seemingly were not checked.

More than 3,000 people were on hand Wednesday as the 31-year-old Kirk, CEO and co-founder of the conservative grassroots organization Turning Point USA, spoke in an open-air courtyard on the Orem, Utah, campus, which is at the bottom of a bowl-shaped area surrounded by buildings, law enforcement officials said.

A gunman fired the deadly shot at Kirk with a high-powered bolt-action rifle from the rooftop of a campus building a substantial distance from where Kirk was speaking, hitting him in the throat, officials said.

The suspect in the shooting, identified as 22-year-old Tyler Robinson, was arrested on Friday night after his father recognized him from surveillance images and video released by investigators, authorities said.

“This is a police chief’s nightmare,” Chief Jeff Long of the Utah Valley University campus police department said at a news conference on Wednesday.

Witnesses told ABC News that the event was not just open to the students on campus, but to the general public as well.

Long said he worked with Kirk’s private security team to establish security protocols for the event, which was the first stop on a nationwide tour of college campuses Kirk launched, called The American Comeback Tour.

“We worked together. He has his team and they do this all over the country. We all know that. It’s not uncommon for them. They’re very comfortable on campuses. And I was coordinating with his lead security guy,” Long said.

Turning Point USA did not respond to an ABC News request for comment.

Long said six campus police officers were working the event, including some in plainclothes who were monitoring the crowd.

“We train for these things, and you think you have things covered, and these things, unfortunately, they happen,” Long said. “You try to get your bases covered and, unfortunately, today [Wednesday] we didn’t. Because of that, we have this tragic incident.”

But multiple witnesses who attended the event told ABC News there seemed to be little to no security at all.

“We walked in, we were kind of surprised because there was like no security check. They didn’t check us for IDs. They didn’t pat us down. You just walked in,” Jasmine Martinez, a mother of five, told ABC News on Thursday.

Justin Hicken, who also attended the event, said he, too, was surprised by the seeming lack of security.

“I just followed the crowd into some of the campus buildings and … once you made your way through the campus buildings, it opens up into a courtyard where the stage or the amphitheater drops down like a pit,” Hicken told ABC News, adding that he also was not scrutinized by any security when he arrived at the free event.

He said that while the crowd was mostly comprised of college-aged people, “There were people of all ages there.”

“There were elderly people with walkers, there were children, there were families. It was a big group,” Hicken said. “I would say it was probably about 97% or 98% pro-Charlie. There were a few people you could tell were in opposition to him being there but for the most part, it was a very pro-Charlie crowd.”

Before the event, an online petition was circulated asking school officials to prevent Kirk from speaking on the UVU campus. The petition stated in part that “Charlie Kirk is known for his divisive rhetoric that often supports policies and laws which aren’t inclusive and can marginalize various communities.” The petition gathered more than 900 signatures.

“We affirm our commitment to free speech, intellectual inquiry, and constructive dialogue,” the university said in a Sept. 3 statement in response to the petition. “The university respects the rights of student clubs and organizations to invite various speakers to campus. As a public institution, UVU upholds First Amendment rights and fosters an environment where ideas – popular or controversial – can be exchanged freely, energetically, and civilly.”

However, Don Mihalek, a retired senior special agent for the U.S. Secret Service and an ABC News contributor, questioned the location of the stage with roofs of buildings surrounding the area where Kirk was shot, given that President Donald Trump was shot at a July 13, 2024, campaign rally at an outdoor venue in Butler, Pennsylvania, by a man who fired from rooftop 400 feet from where Trump was speaking.

Investigators said the gunman who shot Kirk fired an older model imported Mauser .30-06 caliber bolt-action rifle from the roof of a building and appeared to have a clear line of sight to where Kirk was seated under a shade canopy more than 100 yards away.

“The location of the event was in the middle of a college quad, it sounds like, which was surrounded by tall buildings, which present line-of-sight issues,” Mihalek said.

Mihalek added, “In my view, in this day and age, you can’t not do proper advanced planning for an event, especially an outdoor event, and take into account all the standard security measures for an event.”

Mihalek said pre-planning for possible security issues, including access control to the event, line-of-sight issues and monitoring of the crowd, “all has to be baked into the event planning process.”

Robert Boyce, the retired chief of detectives for the New York Police Department and an ABC News contributor, said that from a security standpoint, the outdoor venue should have never been chosen for an event featuring such a controversial speaker.

Boyce further said that the venue for the event shouldn’t have been outdoors.

“For a controversial person speaking in any way, with any kind of petition, any outside threats we don’t know right now, you really can’t have it outside,” Boyce said. “You have to have a door to control and that’s important, especially in these times. We’re really at a different point in our history that’s really hard to believe. But you want to control that door. This way, you know who’s inside and you can walk around and see and identify anybody who’s acting out of sorts.”

Boyce also questioned why the event was opened to the general public.

“It’s inexplicable to me why a university would let outside people come in and watch this on their campus, and that has to be answered,” Boyce said.

In response to the questions raised about the security plan for the event, a university spokesperson told ABC News, “I’m not able to answer those specifics at this time.”

The university spokesperson directed ABC News to a page on the school’s website answering some frequently asked questions about the Charlie Kirk event. Under the question “What security measures were taken?” the website states “Kirk’s lead security staff coordinated with UVU Police Chief Jeff Long regarding the security measures,” echoing Chief Long’s statement during the Sept. 10 news conference.

The website page also said that Kirk had previously visited the school with Turning Point USA in 2019.

The Utah Board of Higher Education – the governing body for the Utah System of Higher Education, which is comprised of 16 public colleges and universities, including UVU – issued a statement last week, saying it will “continue working with state leaders to identify ways to keep our campuses safe and welcoming for everyone.”

The statement added, “We believe strongly that Utah’s campuses must remain places where individuals can share and debate differing viewpoints openly and respectfully. Attempts to diminish that freedom have no place here and we will continue working to ensure our students, faculty and visitors feel safe to express themselves.”