A distinguished American marine biologist was shot and killed by three men in the central Philippines at the weekend. Police said Kent Carpenter, 73, was in a house in Sibulan, Negros Oriental, when the masked men forced their way in and shot him. They stole a laptop, cash, and a backpack before fleeing. Carpenter's companion was injured and is being treated. Investigators are working to determine the motive and identify the attackers. Carpenter had been a lecturer at Silliman University in the Philippines. Officials at Old Dominion University in Virginia say he was a professor there since 1996 and his research shaped conservation efforts around the world.