The need for secure, transparent, and immutable digital evidence has increased, as it is an essential component of criminal investigations. The integrity, transparency, and security of digital evidence are frequently compromised by the conventional system. Blockchain technology has proven to be a transformative solution for maintaining digital evidence in a secure and transparent manner. However, the application of blockchain is limited by its scalability in handling the vast amounts of digital data. To preserve large amounts of digital evidence, this paper thoroughly examines the current Layer 1 and Layer 2 scalability methods, such as sharding, state channels, and roll-ups. We have observed that hybrid scalability solutions can be employed to solve the scalability issues. In this paper, various scalability solutions and consensus mechanisms related to digital evidence are compared. This paper provides a comprehensive literature review, identifies the research gap also suggests future directions for developing scalable digital evidence management solutions.