“Brutalist buildings are characterised by minimalist constructions that showcase the bare building materials and structural elements over decorative design.”
I would welcome expanding my knowledge but what style do you consider buildings of few decorative designs other than their harsh geometric edges and shapes? The inner walls of a prison are often the outer wall. Just straight rows of cinderblock. Inside and outside, the structures lack other architechtural stylings because it creates hiding places or is viewed as extra work/cost during construction.Everything ends in a corner or an edge - no soft edges. As far as my experiences are concerned, that lines up pretty well unless you would rather use the word “spartan” in terms of how little decoration the state puts up.