Sierra Leone authorities have charged 12 people with treason in connection with a failed coup in November, including a member of former President Ernest Bai Koroma’s security detail, the government said on Tuesday. Gunmen attacked a military barracks, a prison and other locations in Sierra Leone on Nov. 26, freeing about 2,200 inmates and killing more than 20 people in what the authorities said afterwards was an attempt to overthrow the government.