civil papers

My son had a warrent for theift out on him. He was picked up held 5 days seen 2 times and all charged were dropped. They said he could be supened into court at a later date. A few days ago an officer came to the door looking for him, said he had " some civil papers for him" he does not live here any more. He was mixed up with the wrong people but for the past 3 months have been working hard to try to get his life on track. His car was stolen 1 day ago but did not call police because he does not know what the "civil papers" might be. He has not done anything wrong that he knows of. What would these so called "civil Papers" might be about?

I am a law school graduate. What I offer is mere information, not to be construed as forming an attorney client relationship.

Could be anything -- from subpoena to lawsuit civil complaint (the people he allegedly stole from suing him in civil court). But they must serve it upon him to do it. Otherwise, if it should later come back to haunt him, he can argue as an affirmative defense, he was never served and thus never had notice.