"In political discourses as well as in many popular movies, omerta often relies on the risks of retaliation. The risk of violence is therefore seen as the main explanation for the silence the police officers are confronted with when trying to carry out their investigations. This article shows that, even though the forms of delinquency found in the French popular suburbs point out more to gangs and networks involved in drug trafficking, limited in scope, rather than mafia-type organisations, the work of the police officers is nonetheless constrained by various obstructions to testimonies that cannot be reduced to the risks of retaliation and anticipated violence. This article thus analyses the relationships between silence and fear, taking into account the forms of social support that varies according to the types of crimes committed."