I thought every country had this, but now I’m wondering if that’s not correct.
From the Canadian criminal code:
Sentence for dangerous offender
(4) If the court finds an offender to be a dangerous offender, it shall
(a) impose a sentence of detention in a penitentiary for an indeterminate period;
But looking it up it is quite contentious. I always assumed it was more of a mental health diagnosis than a sentence. I’d be curious how many other countries have similar provisions .