In Belgium, in youth facilities something like a solid 90% of inmates (children) are not even accused of a crime. Rather their parents have divorced or they "have been diagnosed with ADD" (a condition psychiatrists don't even agree exists in the first place), or ... And their "development needs to be safeguarded".
The remaining 10% (at most) mostly (>80%) are convicted of running away from youth services, about half the time with help from their parents (which is a crime, for children, "statusdelict"). For the remainder the vast majority committed theft, and there are single digit children who committed serious crimes. And while the cells are slightly nicer, not much nicer. The doors are very much locked. Also if the staff judges there to be any risk of you damaging your room, yourself, or they just think you did something wrong, you may spend an arbitrary amount of time in an isolation cell, in 2018 inspections reported cases where 2 weeks isolation cell was done.
You have no rights as a child before the law. You do not have the right to a lawyer. You do not have the right to demand proof. You do not have the right to not be incarcerated if you're innocent (yes, really). You do not have the right to even know what your punishment is. If you're under 12 you do not even have the right to speak during your trial, and above you only have the right to be heard. You do not have the right to know what you're accused of (which may be nothing at all, just that "your development is in danger"). You do not have the right to not be punished twice for the same crime (effectively meaning incarceration can be arbitrarily prolonged, during and even after they've finished, on the say so of the "educators" at the "institution"). You do not have the right to appeal a decision (the judge must allow that, yes, really, needless to say, this is extremely rare). Sentences are carried while an appeal is hanging or being carried out (often you don't have the right to attend your appeal). You do not have the right to education. You do not have the right to books, or library, tv, contact with the outside world, or ...
Those "educators"/guards who tell the judge to extend or not extend your incarceration are employed by companies who have a direct financial incentive to demand extensions (they're paid per "filled bed" and treatments provided). The same is true for the investigators of child abuse. They're paid per investigation ... and per treatment provided.
Needless to say, the system is rife with abuse (and youth services choose the side of the "educators" who commit the abuse in all examples I could find). In several cases in the past 5 years these people got caught sexually abusing children, in one case they got caught pimping out minors.
(As for actual crimes: total number of serious crimes (technically involuntary maslaughter): 2. Theft with violence or other violence was between 20 and 40 for the whole year. Total number of MOF (crimes) cases < 200. Total number of inmates: ~4000)
NEVER EVER cooperate with youth services. Any of them at all. Any kid is MUCH better of in even a very abusive relationship than in the "care" of these assholes. If you think they will physically survive the abuse, I would literally ask you to lie to child services, and to the police to protect children from them. This is the only moral action, and you are protecting those children from a much, MUCH, worse fate.