Casinos like Mandalay Bay “spend millions and millions of dollars on security,” said a surveillance expert who helped install an early version of Mandalay Bay's security systems after it opened in the 1990s. The system he installed had close to 1,200 cameras, and he guesses Mandalay Bay has about 3,000 cameras now.
“They’re all recording 24/7. Anybody who walks through that door is an asset. They’re going to take care of their assets,” said the expert, who declined to be identified because of concerns of future litigation.
But hallways can be difficult for security cameras to capture — they might be too long or too dark to show what's actually happening — so hotels instead put cameras on bottlenecks like elevator banks. “Typically they want to see who’s coming onto the floor and off the floor, and they can tell now who goes into rooms with the keycards,” the expert said.