Hans Staiger was a German national and an Al-Qaeda agent known as "The Recruiter". In addition, Staiger was tasked with spreading the beliefs of the terrorist group across Europe and getting people to join the group, thus increasing their numbers. The European authorities never managed to track him down however, and no photos/DNA of him were ever obtained, but only some recorded calls. Gibbs and Ziva approached the body and eventually decide that justice had been served, and that no further investigation was necessary, thus closing the case for good.