LOS ANGELES — Less than 24 hours after a bullet whizzed across a Utah college campus and claimed the life of conservative activist Charlie Kirk, polarizing figures from across the political spectrum swiftly canceled public events. Rep. Alexandra Ocasio-Cortez, D-New York, decided to postpone a North Carolina stop on the “Fighting Oligarchy” tour this weekend, while Trump allies Steve Bannon ...

Law enforcement responds to the scene where political activist Charlie Kirk was shot during an event at Utah Valley University on Sept. 10, 2025, in Orem, Utah.

George Frey/Getty Images North America/TNS

LOS ANGELES — Less than 24 hours after a bullet whizzed across a Utah college campus and claimed the life of conservative activist Charlie Kirk, polarizing figures from across the political spectrum swiftly canceled public events.

Rep. Alexandra Ocasio-Cortez, D-New York, decided to postpone a North Carolina stop on the “Fighting Oligarchy” tour this weekend, while Trump allies Steve Bannon and Rudy Giuliani reportedly nixed plans for a New York gathering due to “increased security concerns.”

Popular leftist Twitch streamer Hasan Piker, who was set to debate Kirk at Dartmouth College later this month, told Politico he would “wait for the temperature to lower” before holding in-person events again.

Kirk’s assassination comes amid a spate of attacks on high-profile political figures — including two assassination attempts on President Donald Trump — that security experts say will change the way large-scale political events are held, with open-air venues increasingly seen as risky.

“In the current threat environment, outdoor venues for political events should be avoided at all costs,” said Art Acevedo, the former head of the Houston and Miami Police Departments.

Even with a security apparatus as powerful as the U.S. Secret Service, experts say it is incredibly difficult to establish a firm perimeter at outdoor rallies with a large number of attendees. The gunman who opened fire on Trump in Butler, Pa., during the 2024 presidential campaign did so from more than 400 feet away. Kirk was shot from a distance of nearly 200 yards with a powerful bolt-action rifle.

Kirk’s suspected killer, 22-year-old Tyler Robinson, was arrested Friday morning, authorities said. Utah Gov. Spencer Cox said ammunition recovered and linked to the shooting had anti-fascist engravings on it.

A PBS/Marist Poll conducted last year found 1 in 5 Americans believes violent acts would be justified to “get the country back on track.”

Democratic lawmaker Melissa Hortman was killed alongside her husband at their Minnesota home in June by a gunman allegedly motivated by conservative politics. In April, police arrested a man who allegedly tried to set fire to Pennsylvania Gov. Josh Shapiro’s residence while the Democrat slept inside with his family.

Politicians aren’t the only ones being targeted. The killing last December in Manhattan of a healthcare industry executive turned suspected gunman Luigi Mangione into an object of public fascination, with some applauding the act of vigilantism.

With Americans increasingly viewing their political enemies as enemy combatants, researchers who study extremist violence and event security professionals say Kirk’s killing on Wednesday could mark a turning point in how well-known individuals protect themselves.

“The bottom line is, for public political and other figures, it is increasingly difficult to protect them anywhere, but even more so in an outdoor environment because it’s getting harder to screen people and devices in those open spaces,” said Brian Levin, a former New York City police officer and professor emeritus at the Center for the Study of Hate and Extremism at Cal State San Bernardino.

Kirk was being protected by roughly a half-dozen Utah Valley University police officers and a handful of private security guards Wednesday, according to campus security officials. While that kind of presence might deter a close-quarters threat, snipers and other assailants with long-range capabilities would not be affected.

Typically, security professionals seek to create three “rings of protection” around the focus of a public event, according to Kent Moyer, founder of World Protection Group, an international security firm.

The inner ring often consists of barriers and security personnel meant to separate Kirk from the crowd immediately in front of him, not someone hundreds of yards away. In the middle ring, security guards positioned farther from the focus of the event monitor the temperature of the crowd and try to clock individuals acting strangely or becoming aggressive. An outer ring would serve to search bags and screen individuals before they enter the event.

It did not appear there was any screening of attendees at the event where Kirk was killed, and it is legal to openly carry firearms on a college campus in Utah.

Levin said he expects to see drones deployed at similar events in the future, an assessment seconded by Acevedo.

“If you’re going to do an outdoor event you better make sure you have some kind of surveillance of rooftops,” Levin said.

When doing risk assessments, Levin said, police and security professionals need to be cognizant that politicians themselves are no longer the sole targets for political violence.

What Levin called “idiosyncratic actors” are increasingly likely to lash out at those connected to political and policy positions they find unjust. While Kirk was not a politician himself, he was a beloved figure in Trump’s orbit and his activist group, Turning Point USA, has often been credited with driving younger voters to support the president.

“It’s not just elected officials. It’s pundits, it includes corporate people, people involved in policy and education,” said Levin.

But a heavy security detail doesn’t come cheap.

While elected officials are guarded by a range of federal and state law enforcement agencies, political influencers like Kirk must rely on their own vendors as well as security personnel hired by the venues they speak at.

Levin warned that law enforcement assigned to political events should be on high alert for retaliatory attacks in the near future, given the “dehumanizing” rhetoric some have taken up in the wake of Kirk’s killing.

Specifically, he pointed to Trump’s oval office remarks late Wednesday blaming Kirk’s death on “the radical left,” despite the fact that Kirk’s killer had not been identified at that time and federal law enforcement officials had not disclosed a motive in the shooting.

Trump also rattled off a number of attacks on Republicans during his remarks, while making no mention of Hortman’s murder, the 2022 attack on the husband of U.S. Rep. Nancy Pelosi, or the Jan. 6, 2021, attack on the U.S. Capitol — all violent incidents carried out by people who espoused right-wing political values.

“More and more people across the ideological spectrum, though more concentrated on the far hard right, think violence is justified to achieve political outcomes,” Levin said.