The elderly in general, and those with dementia in particular are more likely to be victims of abuse, neglect or self-neglect.

These demented elderly, because of biological aging, psychological disorders of character, behavior and conduct are themselves sources of violence that may lead to medico-legal.

The objectives of our work are to specify the profile of mentally ill elderly dementia and identify the characteristics of their medico-legal.

Our work has focused on all patients older than 60 years hospitalized under the mode of office between 1995 and 2012 in the service of forensic Razi hospital according to article 29 of the law n° 92-83 of the third of August 1992 as amended by the law 2004-40 of 3 May 2004, following a non-legal place due to insanity within the meaning of the 38 article of the Tunisian Penal Code, and which the diagnosis of dementia was increased.

Our study included 7 patients, whose average age was between 65 and 90 years. The majority being married, having a low socioeconomic level. Acts forensic being uxoricides (2 cases), attempted murder (2 cases), attempted rape (1 case), violence against people (1 case), false and corruption (1 case). Almost all committed crimes against people associated with violence.

The diagnosis of dementia was retained and all patients were referred to the neurology department for further explorations.

The type of dementia was noted in 4 cases: mixed dementia, Alzheimer's disease, dementia due to Huntington's disease and dementia due to Parkinson's disease.