Microfisica dell’insicurezza - some facts. May 24th 2000, in a small provincial town in northern Italy (Imola), a social educator - working in a residential psychiatric facility for chronic patients - was stabbed to death by a patient, while bringing him his morning medication. The director and a psychiatrist of the residential facility were subsequently convicted for homicide. The author reports the contents of a conversation he had some time later with a patient, during which he described the judicial procedure he had been involved in. The author then discusses how such an incrimination may impact on a doctor-patient relationship, doomed to mutual distrust, genesis of the microphysics of insecurity. In such a situation, both psychiatrist and patient, become fearful of each other, and most probably engender an anti-therapeutic relationship. For this reason, the author hypotheses that the feeling of social insecurity grows from beneath. Keywords: dangerousness, socially guaranteed position, professional liability, trust, doctor-patient relationship, microphysics of insecurity.