smoking gun
noun/ˌsməʊkɪŋ ˈɡʌn/
/ˌsməʊkɪŋ ˈɡʌn/
[singular] (informal)- something that seems to prove that somebody has done something wrong or illegal
犯错（或犯法的）证据 - This memo could be the smoking gun that investigators have been looking for.
这份备忘录可能是调查人员一直在寻找的证据。 - There's no smoking gun that they have found to date.
迄今为止他们还未发现确凿的证据。
- This memo could be the smoking gun that investigators have been looking for.