Forensic 3D reconstruction
reconstructions (visualization) in forensic field of application is a set of
different computer technologies aiming at the reconstruction of a shooting case
and the explanation of material traces at the scene of crime, on a suspect or a
3D reconstruction is a new forensic tool to assist scientists, attorneys,
judges, and juries to reconstruct a shooting case and explain material traces at
scene of crime, on a suspect or victim. Forensic 3D technology uses a visual
approach and presents critical evidence by use of pictures, video, and
interactive 3D technology. Forensic 3D technology can be used to document crime
scene with relevant traces and allows the expert to take measurements on 3D
model of crime scene back in the office.
Typical Forensic 3D
Typical forensic 3D workflow consists of the following:
· crime scene modeling;
· character modeling;
· inserting the characters in the crime scene;
· simulation of different versions of the shooting incident;
· creation of the version of the ballistic expert.
Recent improvement in laser 3D technology now allows a forensic scientist to solve problems that could not be solved before. For example, in some old unsolved ("cold") crime cases it is not possible to conclude what had happened because mistakes done during survey on scene of crime. In a worst case scenario the scene of crime had been photographed by police officers with cheap cameras and position of some critical traces were not measured properly. Afterwards it showed that it was of vital importance to measure position of the trace as precisely as possible. In cases that the scene of crime is not drastically changed and that recorded objects on the scene of crime are still present it is possible to reconstruct traces of blood or similar important traces with precision of several mm. Fresh 3D model of the scene of crime produced by laser 3D scanner is used to project old photographs taken by police officers. Using photogrammetry algorithms the old photographs taken with uncalibrated cameras are projected to the fresh 3D model of the scene of crime according to the distance and angle of the camera during shooting the photographs. This procedure makes it possible to precisely measure dimensions on photographs projected on 3D model of scene of crime.