The separation between psychosis (Dementia Praecox) acid perversity (m
oral insanity) was a clinical and forensic problem for alienists and t
he notion of perversity remains unclear. Racamier -inspired by Freud's
later work-provides a dynamic approach. Serial killers are studied as
extreme cases of the connection between narcissistic perversion and p
sychosis. Observations are used to study criminal repetition although
the author does not claim to offer a general model: starting from an o
riginal experience -a revelation for the subject- the relapses are org
anised around an experience of a narcissistic orgy accompanied by sexu
al excitement. Absolute control of the object-victim requires the abse
nce of conscious hatred, indifference and the pseudo-fetishisation of
his bodily wastes. Pushed to an extreme, the repetition of the crimina
l act becomes the ultimate despecified common path of all destabilisat
ion of the psychic economy and enters into the service of the splittin
g of the ego.