Police were continuing to negotiate with a man in an armored vehicle after he opened fire on Dallas police headquarters and led dozens of squad cars on a chase that ended in Hutchins. No injuries had been confirmed in the attack early Saturday, though the gunman told police he had been wounded. The man has identified himself as James Boulware, 50, who has a history of family violence and blames authorities for his losing custody of his son, Dallas police Chief David Brown said. The gunman said he was going to blow up police because they “took his child and...