While there are qualifiers for things like mental illness, the system assumes free will by default making rare exceptions for responsibility for people in some states of mind. Whatever that is, it's not determinism.

if a person is not held responsible for the actions they carry out, what can the underlying logic be but a rejection of free will? things will get truly interesting this century as we get better at projecting probabilities based on genetics and personal data; if a man is less culpable because of predispositions, why should we even let him out? this is a fundamental tension in our justice system.