Abstract: Number of cyber crime increases dramatically these days and there are rapid progress on computer and smartphone systems, therefore, forensic investigators have been facing the difficulty of admissibility of digital evidence. To solve this problem, this paper
developed forensic techniques and tools to collect digital evidence for computer systems and Android mobile devices.
Forensics were carried out on both Windows and Linux systems to ensure judicial review of the evidence on the effectiveness of digital evidence with credibility.

Key words: digital forensics, computer forensics, mobile phone forensics, computer crimes, cyber crimes