That makes sense. Scout out the tourist group for a few days and then assault a particular woman/victim the last night, and it is less likely she'll want to stay around and prefer charges. Especially if she danced with the guy who'd been so friendly and nice the past couple of days. Then a pill in her drink and whisk her off to the car. Bingo. This would be quite amusing to macho idiots.
IMO, that is exactly what has happened!!!!