A letter written by Arthur Shawcross in prison is revealing, indicating both emotional immaturity and literate sophistication, and a repressed and devious personality.
"Was it possible that some people were rotten from the start, hopelessly corrupt before environment had an opportunity to effect [sic] them? Was that a reactionary, medieval, thought? It’s been said a great deal of man with the XYY - is a genetically ordained criminal type that inspired so much scientific research over the past few years. Could it be some people can be born less human or civilized then [sic] others? Can it be cause by chemical or genetically reasons that no one had thought seriously about yet? This can be misinterpreted! If I am a chemical or genetic inferiority, then lets look into every aspect of others who may have what I do! Was I born to do evil or trained? … I am a special creature, born more or less than human…"