《九九九谁是凶手》是由高林豹执导的一部悬疑影片，由周文健、徐濠萦主演，于1994年06月17日正式上映。

重案组督察何铁男部下女警Jacky Wong调任便衣警员的头一天，一头狗带领二人到荒野，发现一男子被钉十字架。追查之下，得悉死者大D生前与游定坚、梁志华和陈虎三人最为稔熟。陈虎无故失踪，嫌疑最大。原来陈虎因误杀与他有染的大D妻子沈金莲而慝藏起来，及至陈虎都被杀，案情又再陷疆局。原来四人合资在深圳金屋藏娇，邓燕芳为供妹妹美萍在外升学而甘受凌辱。当游定坚成为第三名被钉十字架的人时，只有梁志华和邓美萍最为可疑。美萍受伤入院之际，志华又被钉十字架，警方顿时束手无策。

经过细心观察，铁男终于解开疑团：推断志华是杀人及自杀的，原来志华与燕芳真心相爱，其余三人不愿离开，燕芳被逼自杀，志华为报仇而计划杀人。为保妻儿日后生活，故佯作被杀的假象，以骗取保险金。而华妻也为了隐瞒真相，杀害美萍，并欲杀铁男及Jacky灭口，不果，并伤重身亡。铁男成全他们，没有揭开真相，让其子取得保险金。

年輕重案組督察何鐵男，憑着天生偵探頭腦屢破奇案，在警界早已享負盛名。不久，鐵男接受了Jacky毛遂自薦，首天上任，她即遇上了一件匪夷所思的怪事—一隻流浪狗前往警署報案。Jacky在好奇心驅使下，拉着鐵男隨小狗跑到荒山，於一密林內發現了一具釘在十字架上的恐怖男屍，沒有證人，沒有證物，只憑一隻“證狗”，二人遂輾轉追查出死者大D的住所，發現了種種跡象，顯示大D的妻子阿蓮及好友陳虎嫌疑最大。正當鐵男的矛頭指向蓮與虎之際，在密林附近找到蓮的屍首；案情越來越複雜，鐵男立刻下令輯捕陳虎歸案。翌日，十字架殺人事件又再次發生，受害者竟是陳虎，案情陷入一片迷惘當中，且涉嫌人物亦越來越多……

CID officers Ho Tin-nam (Michael Chow) and Jacky Wong (Hilary Tsui) follow a stray dog to the crucified body of a truck driver in a remote area. Much of the suspicion centres on his fellow trucker Chan (Shing Fui-on), particularly when the victim's wife is killed as well. When not only Chan, but the nosy stray dog are added to the growing number of victims, attention is focused on an arrangement which the drivers had with a Chinese prostitute named Yin-fong. She had been their secret liaison in Shenzhen, and committed suicide when the men refused to let her stop providing her services to them. Yin-fong's twin sister Mei-ping (Miki Ng) also becomes a suspect, but yet another murder provides her with an alibi. Officers Ho Tin-nam and Jacky are faced with a plethora of red herring leads and an escalating body count before they can bring the real killer to justice.