At entrances to the Wynn resort in Las Vegas on Monday, guards scanned visitors with wands and inspected their bags, creating a 10-minute wait. The new protocol, put in place after Sunday's mass shooting nearby, is likely to become the norm on the Strip.

Casinos and entertainment venues are going to have to take a more holistic approach to security, thinking about rooftops and other potential perches — considering the possibilities for an attack from all angles, said David Shepherd, a former FBI special agent in counterterrorism who was the security director for Las Vegas Sands' Venetian resort.

"We have to start thinking like the Secret Service — start looking at tall buildings," said Shepherd, co-author of the book "Active Shooter." "How far do we have to take it?"

The additional security measures highlight the dilemma facing companies in one of the nation's top entertainment destinations.

How do businesses keep guests safe but not impose such drastic restrictions that the casinos, clubs and shopping thoroughfares no longer feel fun?

One executive at another casino operator said the Wynn's security check at the door is probably the industry's future because there's no other way to screen for people ­carrying weapons.

MGM Resorts International owns the Mandalay Bay hotel where Stephen Paddock opened fire Sunday night on an outdoor concert venue on the Strip operated by the company. MGM canceled all its Las Vegas shows Monday.

The future of live events will likely include anti-sniper teams, metal detectors and better separation of audiences so they can be evacuated quickly and first responders can get in, said security consultant Ed Davis, Boston's police commissioner from 2006 to 2013. Whether the Las Vegas massacre sparks broader changes in gun laws remains to be seen.

"I would have thought that would have happened after Sandy Hook," he said, referring to the Connecticut school shooting in 2012. "This doesn't happen in other countries and that's because of how we regulate or don't regulate guns."

Since the Las Vegas attack was at an outdoor venue, there wasn't a natural exit to run to, and concertgoers were vulnerable from above, Shepherd said. It's also not enough to screen customers for firearms.

"In this case, he's [the shooter] not even at the event," he said.