check with your local police department some states have different statutes but nationwide I know that adults have a deadline from the point of remembering the abuse that they repressed. at the very least he can make a police report that it happened so that it official record so if the guy does it again your son can testify that it happened to him which would add credibilty to the new person the guy got to. Who knows there just may already be another victim out there right now trying to prosecute that your son could help which would help your son process his ouw situation. Know though once na official report is made the abuser will be notified that that report is now a part of his offical police report. If the abuser is anything like mine were you could be in for a ride that you need to prepare yourself for before making the report. I got threats with arrest for libel and slander and threats of being committed to mental facilities, and so on. So let your son decide what he is ready to do about what happened to him. It happened to him so he is going to be the one that gets the majority of the fallout of telling about it. You and other family members will also need to prepare for possible fall out before the report is made especially if the abuser is in your local area. Check out the services of rape crisis centers in your area and the police services should there be fallout from the report being made. hang in there