Virtually Evident

Computer-based scene reconstruction is a method for answering specific forensic questions in the context of accident or crime scenes. For the resulting 3D reconstruction, the use of virtual reality (VR) technology is a novel presentation form. For the presentation to a prosecutor, the need to put visible content into context awards special significance to the moderator, especially as in a VR presentation the head mounted display (HMD) cuts VR users off from their natural environment. We analyze use cases for the parties involved in the courtroom VR presentation and consider the author, moderator and spectator roles and their corresponding session types for creating, directing and watching the presentation. A prototype system has been implemented to allow for suitable VR interactions for the three roles. An evaluation of the system with 12 participants assuming the role of the spectator yielded positive results with regard to the user experience and utility.