One of the most striking phenomena of criminal trials in China is the absence of witnesses. Intrigued by this feature in the Chinese courtroom, I embarked on a PhD study to explore how the Chinese criminal justice process works without introducing witnesses' live testimonies. This inquiry led me to examine the functioning of the criminal dossiers, which carries this study through various stages of the Chinese criminal justice process. The primary research method that I relied on in this study is participant observation, which is suitable to observe complex criminal processes within the legal institutions. Such a position allowed me to be an interpreter of the data yielded by the participation and a knower who understands the shared ideology, values and dilemmas of the legal personnel. As an unstructured approach, the open-endedness and exploratory nature of participant observation enabled me to identify key issues in the field with sufficient flexibility.