This report presents a computer forensics case study, focusing on a real-world criminal investigation involving a missing person and subsequent murder. The case details the disappearance of Qi Yu and the suspect, Shuo Dong, including the evidence found on the suspect's mobile phone, such as internet search history and pornographic images. The report then evaluates the use of forensic tools like Cellebrite UFED and FEITA digital inspection station in the investigation. The report highlights the importance of these tools in data acquisition, logical and physical extraction, and the analysis of mobile phone data to establish a link between the suspect and the crime. The report concludes by emphasizing the significance of digital forensics in criminal investigations, particularly in the context of mobile phone evidence, and its role in presenting evidence in court.