We adopted my 10-day old niece on 12/17/04. We adopted her through the state as the mother's parental rights were terminated. We received the child when she was only 10 days old. My brother is the alleged father and no testing was involved. He was served and signed papers when the child was less than one month old, relinquishing his rights to the child. 3.5 years later he had his drivers license revoked because they are stating he owes child support for the child. My question is: should he owe child support for any period prior to the official adoption if he relinquished his rights?

It doesn't sound like it. If he was never ordered by the court to pay child support, then he shouldn't have to. The adoptive parents are the legal parents and are the ones legally responsible for providing financial support. It sounds from your post that your brother was never even proven to be the father. It sounds like something just slipped through the cracks here. Your brother should speak with an attorney. A competent attorney should be able to straighten this out without too much difficulty or expense.