ˋㄐㄧㄚㄗㄨㄟˋyùjiāzhīzuìㄏㄜˊㄏㄨㄢˋˊˊhéhuànwúcí

欲加之罪,何患无辞
  1. 罪名別人總是可以藉口 面對流言蜚語攻擊欲加之罪,何患無辭」」。

If you want to condemn sb, don't worry about the pretext (idiom, from Zuozhuan 左傳)​; one can always trump up a charge against sb, Give a dog a bad name, then hang him.