In my opinion, the most important feature in an evidence chain of custody tool is data integrity tracking because maintaining the authenticity and reliability of digital evidence is critical during investigations. A strong chain of custody system should record every action performed on evidence—such as who accessed it, when it was accessed, and what changes (if any) occurred—through secure logging and tamper-proof records. This helps ensure that evidence remains trustworthy and legally admissible throughout the investigation process. While features like access control, audit trails, encryption, and secure storage are also essential, preserving data integrity is the foundation of a secure and reliable digital investigation because even minor doubts about evidence authenticity can impact the credibility of the entire case.