With eight Marines charged in connection with the deaths of 24 Iraqi civilians, the Marine Corps sent a clear message to its officers: They will be held accountable for the actions of their subordinates. In the biggest U.S. criminal case involving civilian deaths to come out of the Iraq war, four of the Marines — all enlisted men — were charged Thursday with unpremeditated murder, the Associated Press reported today. But the remaining four Marines in the case are officers, the highest ranking among them a lieutenant colonel. They were charged with dereliction of duty for failing to report or properly investigate the killings in the Iraqi town of Haditha last year. The case marks the largest number of U.S. officers to be charged in an alleged crime since the start of the Iraq war, said John Hutson, a former Navy judge advocate general.