Digital forensics is an emerging research area and is a truly multi-disciplinary subject that involves at least computer science, law and criminal justice. With the advancement of technologies, crime investigation, especially on digital evidence, becomes difficult. This not only poses challenges to computer scientists and law enforcement units on how to identify, preserve and collect digital evidence from different platforms and media such as Internet, mobile phone, cloud system, and emerging storage devices, but also poses challenges to the legal systems on what kind of digital evidence is admissible to courts and what needs to be amended and added in the ordinance.