刑事审判的中心问题是被告人的刑事责任问题,因此庭审证明的对象往往集中在“七何”上,却忽视了对警察侦查行为合法性的证明。而警察的侦查行为是否遵循法定程序有时对认定嫌疑人是否犯罪以及罪行严重与否存在重大关系。因此笔者主张将侦查行为的合法性纳入证明范畴并由警察以证人身份出庭通过交叉询问来证明。 The central issue of criminal trial is the criminal responsibility of the accused. Therefore, the subjects of trial proof tend to focus on the “Seven Hezuo” but ignore the proof of the legitimacy of the criminal investigation. Whether or not the police investigation is in compliance with statutory procedures is sometimes of great significance to the criminalization of the suspects and the seriousness of the crimes. Therefore, I advocate the legitimacy of investigation into the scope of proof by the police as witnesses to appear in court through cross-examination to prove.