You need a lawyer for a legal, current and correct answer.
....obviously jail
He is currently in jail for conspiracy to commit murder and illegal posession of a firearm.
That will depend on the exact law under which a person is charged. In some cases that could be a very large find and jail time. Unless we know what the exact charge is, we really can't give you an exact answer.
possession of a firearm.
For firearms charges, you can typically expect to serve jail time.
Jail is one, if you are not in compliance with applicable laws.
5 years in a Federal prison.
If unknowingly, that is not a crime.
Depends on the laws where YOU live, and what the prior convictions were for. No one answer.
You need a good lawyer to get a legal, current and correct answer
You will have to ask a lawyer familar with firearms law where you live.
You need to talk to a lawyer for a legal, current and correct answer.