>> soledad brock often visits the cemetery in hollenbeck. >> give me the serenity, good, to acce god, for the things i'll never be able to change. >> reporter: ronald brock was a marine, angel, a gang member. they looked almost like twins, but their lives took two very different paths. both, however, were gunned down in the same year at the same house where they grew up in hollenbeck. >> people tell me it's time to move on and forget. but i don't think anybody understands that your whole life was gone seven years ago. >> reporter: seven years after their deaths, five years after we first reported their stories, detectives say they have solved one of these hollenbeck murders and there's a surprise twist in both cases. the hollenbeck area covers 16