In this paper we introduce DIORAMA based forensic analysis of mass casualty incidents (MCI) using video sequences. The video sequences captured on site are automatically annotated by metadata, which includes the capture time and the camera location and viewing direction. Using a visual interface the MCI investigators can easily understand the availability of video clips in specific areas of interest, and efficiently review them. The video-based forensic analysis system will enable the MCI investigators to better understand the rescue operations and subsequently improve training procedures.