The use of psychoanalytical approach in a forensic evaluation of a family with difficult to think is reported.This kind of family presents difficulty or incapacity to face and solve conflicts due to an impossibility to dealwith stress related to it. This incapacity does not leave space for thought, so the tension created has to be actedout in a schizoparanoid form of conduct. The lack of impulse control is characteristic of these families whichleads the justice system to impose legal limits to them. The intervention of a psychologist as an expert witnessis illustrated by a case which highlights this contribution to the justice system.