The horrific Islamic State-linked terrorist attacks in Paris in November 2015 illustrated another troubling reality: family-affiliated terrorism. More specifically, French nationals and brothers Ibrahim and Salah Abdeslam participated in carrying out the attacks, with the former conducting a suicide bombing at a Paris restaurant, and the latter renting a car that delivered attackers to Bataclan concert hall.

Now an international fugitive, Salah previously served time in prison for armed robbery with the mastermind of the Paris attacks Belgian Abdelhamid Abaaoud. During a police raid in Paris later that month, Abaaoud was killed with his cousin, Hasna Ait Boulahcen. Aitboulahcen and Abaaoud were killed during a standoff with police.  Prior to his demise, Abaaoud recruited his 13-year-old brother to join the Islamic State.