This one IS going to come in handy.
This is wrong, you can't say this in danish plus it's grammatical wrong.
You would say
Betjenten vil ikke lade mig se mine forældre, mens jeg er i fængsel.
Det andet er for direkte oversat og forkert.
This goes to show how much of the english grammar came from old Norse.
So vil is used to make the future tense?
No vil is just an verb, but is one of the "hjælpeverber" that can be used to create futurum. Danish futurum is very simmilar to German.
Wouldn't there be inversion for "jeg er..." in one sentence?
No because 'mens' is a conjunction that conjoins two main clauses
why the officer is not öffize?