在这部确证：警视厅搜查3课剧情/犯罪片中,在警界堪称“黄金一课”的警视厅搜查一课，集结了日本全国都道府县最优秀的刑警，专事处理杀人、放火、抢劫等重大刑事案件，成为所有胸怀正义与热情的有志青年矢志奋斗的目标。25岁的生活安全课女警武田秋穗（荣仓奈奈 饰）正是这群青年中的一员，然而事与愿违，一番努力过后她最终被分配到搜查三课。与黄金一课不同，三课主要负责日常里小偷小摸的寻常案件，供职于此的刑警也多懈怠乏力。幸运的是，一度失落的秋穗遇见了拥有二十多年追查盗贼经验的警部补萩尾秀一（高桥克实 饰）。在萩尾的提携下，秋穗与各种各样的盗贼交手，体验到完全不次于搜查一课同仁们的荣誉感……
本片根据今野敏的小说《确证》改编。
Akiho Takeda is assigned to #3 investigation team for The Tokyo Metropolitan Police Department. On her first day at work, a burglary takes place at a jewelry store in Shibuya. The case though is taken by the #1 investigation team which Akiho hoped to join. Nevertheless, Akiho goes secretly to the jewelry store where the theft took place. Later, a safe at a jewelry store in Roppongi is broken into. Stolen from the safe is the diamond called "Besu". The "Besu" is one of three diamonds that makes up the "Kuraida Family's Three Sisters". The other two diamonds are "Ani" and "Kyasari". The diamond "Ani" was stolen from the jewelry store in Shibuya, that occurred a few days earlier. Several people believe the two diamond thefts were done by the same person(s), but Akiho mentions the techniques used by thieves are different. Yet, Akiho believes there must be a connection between the two cases.
