A few days ago I dropped 13yo off a a skate park located in a village...when I say village it's a bit of a rough area, cut off from the rest off the town, so everybody knows everybody else and the other kids would have known he's not local.
DS has very good social skills and was chatting to some other kids playing there. He had a go one someone else's scooter, and while he did sons boys came along and had a go on his scooter, and wouldn't give it back, but I think they would have eventually.
A girl (DS said she looked about 13) was also there with these boys and picked up DSs bag and started looking through it saying she was a crack addict and needed money. DS was nervous about her finding his GoPro and phone, so handed her £5 from his pocket which she took.
She and the other kids walked off, and DS phoned me to collect him.
DS didn't tell me this happened, but told DH that evening when he got home.
DH then told me, and my immediate reaction was to report it to the police. DH is reluctant. Having thought about it, no crime was committed as DS handed over the £5. 
DH and I have both told DS he did the right thing.