[sǐ wú duì zhèng]   

死    无    对    证    对证：核实。当事人已死，无法核对事实。

死无对证，成语，指当事人已死，无法核对事实。

There was no testimony of witness after the conspirator passed away

死心踏地    死声淘气    死重泰山    死灰复燃    死生荣辱