B2idiom
Barking up the wrong tree
엉뚱한 사람(것)을 의심하다 / 잘못된 방향으로 접근하다
To pursue the wrong course of action or blame the wrong person.
예문
If you think I leaked the information, you're barking up the wrong tree.
The investigation was barking up the wrong tree for months before the real culprit was found.