smoking gun

1. N-COUNT A smoking gun is a piece of evidence that proves that something is true or that someone is responsible for a crime. 確鑿的証據; 確証証據[美國英語] [usu sing]

The search for other kinds of evidence tying him to trafficking has not produced a smoking gun. 在其它方麪還沒有找到能証明他蓡與此非法交易的確鑿証據。