The digitalization of public and governmental services has enhanced the efficiency, transparency, and collaboration in forensic investigations. However, digital forensics faces critical challenges related to maintaining the integrity, authenticity, and trustworthiness of forensic evidence. This paper addresses how to preserve the integrity of forensic evidence throughout its lifecycle and the balance of trust among stakeholders. We propose a blockchain-based digital forensic system, ForensicChain, that securely records, updates, and verifies case-related data while adhering to legal and technological aspects. Our method leverages Merkle trees to generate cryptographic fingerprints of case files, allowing efficient tamper detection. The system ensures that authorized actions are recorded, maintaining a fully auditable record of modifications. We demonstrate the practicality of our proposed solution through a proof of concept implementation using the Cardano blockchain.