"the smoking gun" in Chinese (Simplified)
确凿证据铁证
Definition
“The smoking gun”指能确凿证明某人有罪或某事属实的明确证据，常用于调查或犯罪情境。
Usage Notes (Chinese (Simplified))
属于非正式表达，常见于新闻报道、法律和调查情境。强调直接、无法否认的证据，不是字面意义上的“冒烟的枪”，只作比喻。
Examples
The police found the smoking gun in the suspect's car.
警方在嫌疑人车里找到了**确凿证据**。
The email was the smoking gun in the investigation.
这封电子邮件是调查中的**铁证**。
They still haven't found the smoking gun to prove he's guilty.
他们还没有找到能证明他有罪的**确凿证据**。
That document was basically the smoking gun everyone was waiting for.
那份文件基本上就是大家都在等的**铁证**。
Journalists spent months searching for the smoking gun that would break the story wide open.
记者花了几个月才找到能让事情曝光的**确凿证据**。
It looks bad, but unless we find the smoking gun, we can’t accuse anyone yet.
情况不妙，但除非我们找到**确凿证据**，否则还不能指控任何人。