U.N. envoy rips U.S. over investigation into drone attacks overseas . Private contractors protected by `` zone of impunity , '' envoy says . ` The government has failed to effectively investigate and punish lower-ranking soldiers for such deaths , and has not held senior officers responsible , '' Alston said . Score: 7
U.N. envoy rips U.S. over investigation into drone attacks overseas . Private contractors protected by `` zone of impunity , '' envoy says . Score: 7