Russell and Finlay must confront a serial killer case from their past while working in Seattle when a copycat killer suddenly emerges in Las Vegas.

　　The CSI team investigates a well-orchestrated bombing at the funeral of Officer Franklin Clark.

　　Under the direction of new boss D.B. Russell, the team tackles cases involving a wild shootout on a Las Vegas tram car, and the death of a deer hunt

　　CSI的故事背景设在赌城拉斯维加斯，以真人真事改编，讲述刑事警察局的法庭犯罪调查员如何在作案现场取得证据破案的故事。调查员的名言是“死尸会说话”，他们利用指纹、鞋印、子弹壳、血迹、毛发、纤维、尸体伤痕等微小证据，经过仔细的分析研究后，寻得破案的关键。 解开谜团的过程颇有吸引力。

　　CSI的第九季将于十月十日重装上阵。虽说是CSI系列中最晚登场的一个，然而，且不提爱好者们的反映，单就已发行的宣传片来看，Gil grissom和他的小队所带来的紧张刺激也绝不会是排在倒数第一的。在Grissom（William Petersen饰）缓缓道来的画外音中拉开序幕，CSI第九季的首集

　　While Ecklie fights for his life after his shooting, Russell's patience begins to wear thin as the team tries to get to his kidnapped granddaughter

　　四位园艺俱乐部会员的生活被丑闻、恶作剧和一个共同的秘密交织在一起——一桩无人愿意提起的谋杀案。