Attorney General Eric H. Holder Jr. has decided not to seek the death penalty against a former Guantánamo detainee who was ordered by President Obama to face trial in a civilian court in New York. Mr. Holder communicated the decision to federal prosecutors in Manhattan on Friday, and they in turn informed the federal judge who is presiding in the case. “You are authorized and directed not to seek the death penalty against Ahmed Khalfan Ghailani,” Mr. Holder wrote to Preet Bharara, the United States attorney for the Southern District of New York. Mr. Ghailani faces federal charges of conspiring...