Mexico City — On the stove, a frying pan with chunks of flesh. In the refrigerator, a leg and part of an arm, both deboned. The bones were stuffed into a cereal box. Mexico City police made the grisly discoveries this week as they arrested the man the Mexican press is calling the nation's first cannibalistic serial killer. Police said Jose Luis Calva Zepeda, 40, was arrested Monday and being held for "probable" homicide after an investigation into the disappearance of his girlfriend. Investigators found the mutilated body of Alejandra Galeana, 30, in Calva's closet and believe Calva killed and...