The purpose of digital forensic applications is to determine the flow of events as they unfold, before, during or after the alleged incident occurred. The need to identify the cause of an incident, the flow of events preceding the incident as well as prove the consistency of potential evidence recovered from the alleged incident demands a proactive approach to the designing of digital forensic applications employed in the investigation of such incidents. In the field of digital forensics, applications are used to unravel the cause of incidents, especially during acquisition, analysis or examination of potential digital evidence. The frequent updating of digital devices that are susceptible to involvement in digital crime incidents is a huge challenge to digital forensic investigations. To proactively overcome this challenge, this paper proposes an architectural requirement engineering specifications (ARES) process for the design of digital forensic (DF) applications. The proposed ARES process outlines the design process of DF applications using the online neighbourhood watch (ONW) system for its case study. The result shows that in employing the ARES process in designing DF applications, modifiability, pluggability and maintainability features and changes in legal requirements are achieved, thereby accommodating the constant upgrade/changes associated with electronic devices operating systems (OS) or hardware which may sometimes be involved in DF investigations.