Arrest, Search, Seizure, Warrant warrant in another state

[javelar]

My son, who is in the military and recently returned from overseas, was detained by customs and state police. Apprantly a warrant for his arrest was issued in florida, for some thing that happed over 4 years ago. They could not figure out why so they released him. He has served his country for 3 years now. What does he need to clear this up. Does he need to hire a lawer in florida or can he do it from out of state? Also the actions he is accused of happend when he was 17.