The killing of Brian Thompson, CEO of UnitedHealth’s insurance arm, outside of an investor meeting at a Hilton hotel in Midtown Manhattan prompted an immediate re-evaluation of longstanding security practices across corporate America.

Those who advise companies on security issues say threats against executives are rising, fueled by social media, a fraught political environment and broader resentment toward corporate America and big business.

“The environment is explosive right now,” said former Boston Police Commissioner Ed Davis, who now consults with large companies on how to mitigate security risks. “The threats are evolving and getting more violent.”

“The challenge of executive protection and executive security has become much more complex and much more challenging,” said Brian Stephens, a former chief security officer at Bank of America.

Companies’ level of executive protection runs the spectrum. Some executives have bodyguards with them all day. Others only during the workday. Some none at all. Thompson was walking alone from his hotel to the business meeting at the Hilton when he was shot in a targeted attack, according to police.

A number of executives employ an advance staffer who walks ahead of the executive, checking a scene for any possible risks or suspicious people. Other executives are chauffeured by armed drivers.

Corporate security officials and their advisers typically closely monitor social media for threats against top leaders. But well-publicized public events, such as investor meetings, can pose a particular security challenge, especially if an executive must enter the venue from only a few locations.

Such high-profile incidents have led to re-evaluation of security practices, said Michael Evanoff, a former State Department assistant secretary for diplomatic security who now works on corporate security. “It’s a shock to the system,” he said. “It’s a wake-up call.”

As we have seen with this tragic incident, executive protection and corporate security must be taken seriously. We provide our clients with custom tailored services designed to give them peace of mind and let them focus on their mission.