These offenders are sent to hospitals or prisons where they receive treatment while detained over an indefinite period. Although sexual psychopathy laws have existed for more than 50 years, their effects are only recently being evaluated in a few States. Enactment, amendment, and repeal of such laws have occurred in the absence of empirical support, and clinical issues have become subsumed in legal debate. Institutions to which sexual psychopaths are sent, whether hospitals or prisons, invariably get caught in the legal crossfire. The authors examine some of the issues surrounding sexual psychopathy laws that focus on sexual psychopathy as a diagnostic entity and ethical considerations. They conclude that costs of sexual aggression need to be calculated beyond the simplistic economics of imprisonment versus treatment. 25 references