Nowadays, one of the critical challenges in forensics is analyzing the enormous amounts of unstructured digital evidence, such as images. Often, unstructured digital evidence contains precious information for forensic investigations. Therefore, a retrieval system that can effectively identify forensically relevant images is paramount. In this work, we explored the effectiveness of interactive learning in improving image retrieval performance in the forensic domain by proposing Excalibur - a zero-shot cross-modal image retrieval system extended with interactive learning. Excalibur was evaluated using both simulations and a user study. The simulations reveal that interactive learning is highly effective in improving retrieval performance in the forensic domain. Furthermore, user study participants could effectively leverage the power of interactive learning. Finally, they considered Excalibur effective and straightforward to use and expressed interest in using it in their daily practice.