Fifth amendant right pertaining to information subpoenas

Just received an arrest warrant notice from a constable in New Jersey for failure to answer an information subpoena on a credit account. My younger brother stole my identity, opened credit accounts running up debts, eventually ruining my credit. I didn't press charges because he's an addict. I will plead the fifth amendment when I'm in front of the judge. My question is what can I expect from the judge? Any insight or prior experience in this area would be appreciated.