I used to work in hotels, graveyard shift where all the weird stuff happens. It's also true that full moons bring out even weirder stuff. We've had everything from people showing up, claiming to be the husband or wife of x, and please give a key to the room. Our policy was to give keys only to actual registered guests, but less honest staff wouldn't care, I'm sure. Also, when it was busy, staff didn't always ask for ID from the person requesting the key - this being after the initial check-in, of course.
Yep, theft is common. It doesn't help that some of the guests are really really stupid, leaving key cards lying around or announcing their own room numbers in front of strangers. Prostitutes are also common - guests call an escort agency and the prostitute shows up. We usually got a half dozen a shift on a busy weekend - a half dozen of the easily recognizable as such, that is.
(We usually made bets amongst ourselves as to how long the prostitue would last. Really fugly ones would leave within three minutes. Yeah, not politically correct, but hey, we were working the graveyard, ya know?) Easy for prostitutes to rob them blind. Our security was very vigilant about not having prostitutes in our bar or lounge, though respectably dressed women weren't targeted for kicking out.
We've had attempted/successful murders, suicides, rapes at our hotel (complete with police line-up in the lobby on my shift - I was the duty manager), and even an illegal abortionist working out of the hotel for a month before he was discovered. We've had undercover cops do stake outs from hotel rooms. In the year and a half I worked in the one hotel, I must have filled out four or five dozen police reports.