Since ppl exaggerate individual cases to a generic form, i remain sceptical about "gang of 12 year old". not to say, it doesnt exists. everything is hyperbole on the internet.
It’s quite common for migrant families to takes a few years off their kids age when they arrive, so they’ll adapt more easily, learnt the language and whatnot.
This makes sense to me, to change the birthdate, to get additional support. A lot of young people looking a tad older. But when crimes are reported, where do officials get the birthdates from? Or do they reporting most likelies?