One afternoon in May, 1990, Robert Kosilek murdered his wife, Cheryl. Brutally. He strangled her with piano wire, virtually decapitating her, and left her body in a mall parking lot in a suburb of Boston. Since his conviction, Kosilek, now 64, has been serving a life sentence at Norfolk, a high-security prison for men. For years Kosilek has been a member of the "sisters," a particularly violent, sexually deviant subset of the prison population. But in 1993, Kosilek decided to do a complete makeover, changing his name to Michelle, letting his hair grow long, and dressing as a woman in...