Crime scene reconstruction. Screen display of some three-dimensional (3D) computer models that are used to reconstruct crime scenes. The models seen here are a dead man lying next to broken glass, and a car (green, upper right). The dead man has a bullet trajectory arrow pointing from his chest. Detailed recreation of a crime scene can allow investigators to extrapolate from the known evidence and deduce what may have happened. For example, the bullet trajectory may tell them where the killer was standing, and indicate which areas to investigate for more evidence. Reconstructions are also used in courts of law.