Greene County officials say a man who is suspected of killinga teenager last week thought the teen was a police informant. A GreeneCounty sheriff’s detective says 17-year-old Robert Wilson was shot whileriding in rural Greene County with three other people. They stopped nearthe Little Sac River and one of the men shot Wilson in the back of the head. Twenty-two-year-old Lucas Campbell has been charged with first-degreemurder. Another man in the car was charged with felonious tampering withevidence. Officials say Wilson was not an informant.