A gunman who held police at bay for 48 hours while he kept his former wife prisoner in a Euless, Tex., convenience store where she worked was shot to death by officers who stormed the building after he killed her, authorities said. The victims, Malone Mataele, 27, and Cassandra Mataele, were immigrants from Tonga, in the South Pacific. Police had allowed Mataele's brother, who was not identified, into the store in an effort to end the impasse. A police officer was shot and wounded shortly after the incident began when he responded to a silent alarm. The gunman had fired several shots inside the store during the ordeal, but there were no other injuries.