I'm assuming the "four others" were juveniles. It's amazing that this thread has gotten this far with someone not asking about parental control. 'Just goes to show that few people on this forum actually expect parental supervision from parents in the general public anymore.
Parental control? The story states up front that they were all from upper middle clas homes. IOW, the parents were probably too busy at the office, golf course, whatever, to be bothered by the 'kids'. "Here's some money, go entertain yourself at the mall" only goes so far before the 'kids' get bored. Parental control is about as contemporary as an 8-track player anymore.