(a) Up to approximately one month after the assassination, little or no attempt had been made by the security forces to determine the movements of this suspect truck immediately prior to, or immediately after, the explosion.
(a) 暗杀事件发生后约一个月，安全部队根本没有或不设法确定爆炸即将发生前或发生后该辆卡车的移动情况。