The old adage about being wary of strangers proved particularly telling in the case of Frank, a faceless, nearly nameless serial killer who moved across the highways of the United States in a trailer rigged for mobile dissection. Agent Gideon surmised that Frank maybe the most prolific serial killer of all time, with body parts strewn about nationwide with the same cutting pattern, and a body count well into the triple digits.
Frank also has the distinction – so to speak – of pushing Gideon over the edge. The BAU’s most talented profiler basically gives up after Frank kills a good friend of Gideon’s in his own apartment and then jumps in front of a train with a mentally disturbed woman who thought Frank was in lover with her. It was one of the rare instances that an UnSub escaped justice, and considering the capacity of Frank’s transgressions, that may be the worst crime of all.