Background: Researches and anecdotal reports indicate that suicide rates may be higher among members of law enforcement than those in other occupational categories.In France, there is no recent study on suicide risk among national police forces.Our objectives were to estimate suicide mortality of French national police forces and to compare it to the general population and other occupational groups; and to identify the determinants of suicide mortality.Methods: All available data of the Home Ministry were used to estimate suicide mortality among national police forces.Mortality rates were then compared to those of the general population (data of the French centre of medical causes) and to those of prison staff (data of the prison administration of the Ministry of Justice) using standardisation methods.In a second step, all suicides of police officers of the year 2008 (n=49) were investigated by interviewing key informants.For each case three informants were selected: a member of the family or a close friend, a colleague and a supervisor.Data were collected using standardized questionnaires exploring socio-demographics characteristics, life events, social integration and support, health services use, mental health, occupational stress, impulsivity and aggressiveness.All these information were summarized in a time table life trajectories of all life areas.Each case was then appraised by at least two experts to conclude on the determinants of the suicide.Results: Between 1998 and 2010, the mortality rate among French police officers was equal to 33 p 100,000.After adjustment for gender and age, this was statistically larger than suicide mortality in the French general population (+36 %) and smaller than the suicide rate of French prison staff.In more than half of cases, police officers who committed suicide used their service weapon.39 cases of suicide were investigated (response rate: 83%).All deceased police officers were suffering from psychological distress (most of them from depression).After mental health, the main cause of suicide was problems in the married life (70 % of the cases).Finally, four distinct types of life trajectories could be identified by a qualitative analysis.Discussions: it is the first time such a study was performed in France and results are concordant with those of the literature.This study showed that there was not one single profile of life trajectory: screening and support of police officers in distress have to be prioritized.Moreover results suggested that the availability of the service weapon during off-duty period should be reconsidered.This study helped the Home ministry to elaborate and improve strategies to prevent suicide among police officers.