Underwater and Underground Crime Scenes ∗ ∗The authors are indebted to Colonel Jean-François Voillot, former head of the Criminal Intervention National Unit of the Forensic Research Institute of the French Gendarmerie in Rosny sous Bois, France (IRCGN), and to Warrant Officer Denis Gagnier serving at the Forensic Cell of the Gendarmerie District Command of the Pyrénées-Atlantiques, for having contributed excellent content for this chapter.