withdrawal of case

One of my friend has been taken down in a case of fight amongst some boys but he wasn't involved in it. This case is going on from 2013 and still no judgement is taken on it. All the other accused have left the country. Is it possible that if the complainant is requested to take back his case, my friend will be free of the charges? or is there any other way that he can be helped? he is a student and this case is affecting him a lot. Please experts reply.