XALAPA, Mexico — Regina Martínez’s death was brutal. Someone broke in through the metal door from her beloved garden patio, the tiny patch of tranquility that kept her from moving from her modest cinder-block home to a safer location.The intruder probably surprised her in the bathroom, from behind, investigators believe. At barely 5 feet tall and 100 pounds, she scratched and struggled to fight off her attacker, leaving skin under her fingernails. The assailant broke her jaw with brass knuckles, then wrapped a rag around her neck, squeezing the life out of the region’s best hope for...…XALAPA, Mexico — Regina Martínez’s death was brutal. Someone broke in through the metal door from her beloved garden patio, the tiny patch of tranquility that kept her from moving from her modest cinder-block home to a safer location.The intruder probably surprised her in the bathroom, from behind, investigators believe. At barely 5 feet tall and 100 pounds, she scratched and struggled to fight off her attacker, leaving skin under her fingernails. The assailant broke her jaw with brass knuckles, then wrapped a rag around her neck, squeezing the life out of the region’s best hope for...WW…