A former British army officer who helped found the White Helmets volunteer organization in Syria, was found dead in Istanbul early Monday, Turkish officials and the group said. James Le Mesurier’s body was found near his home in the Beyoglu district by worshippers on their way to a mosque, the state-run Anadolu news agency reported. The Istanbul governor’s office said “comprehensive administrative and judicial investigations” had been initiated into Le Mesurier’s death.