To assess the scope and nature of terrorism in 2016, the Los Angeles Times sought to chart the worldwide toll of deaths and injuries in a single month. From government and police reports, terrorism databases, news accounts and their own independent reporting, Times journalists in the U.S. and around the globe compiled a record of every fatal act of terrorism during the 30 days of April. They confirmed 858 deaths in 27 countries. An additional 1,385 were injured. Recent attacks in Paris and Brussels, San Bernardino and Orlando, Fla., have left Americans and Europeans feeling besieged. But the data show...