In the aftermath of the Paris terrorist attacks earlier this month, perpetrated in the name of Islam by three gunmen born and raised in France, there has been wide discussion in France about how hard-line Islamists succeed in enrolling a section of the country’s disenfranchised youths into their midst. Beyond the influence of extremist networks that operate in public places, notably a number of mosques, the role that prison plays in the recruitment of potential jihadists has been highlighted, notably by French Prime Minister Manuel Valls. Shortly after the attacks, he suggested that jailed radical Islamists may be grouped together in special quarters in prisons to limit their current opportunities of converting fellow prisoners to their cause. Mediapart’s Joseph Confavreux and Carine Fouteau sought out the opinion of Jean-Marie Delarue, who until July 2014 served for six years as France’s general inspector of prisons. In this interview he argues why he believes the proposition is misguided and potentially dangerous.