A murder scene, an auto accident, a collapsed building, a dilapidated stairway where a fall led to severe injury – Paul Francis has used laser scanning to document these and other scenes for the Toronto Police Service, and for private investigators seeking evidence in civil suits. Francis, vice president of Northway-Photomap Inc., Toronto, showed SPAR 2005 attendees how evidence gathered with laser scanning can be more compelling for juries than simple photographs – his firm has created 3D animations of scenes, and even 3D physical models that can go into the jury room. 3D digital models also help investigators analyze what happened in a crash – measuring the vehicle deformation helps determine speed at impact and other contributing factors. Scene capture that's both fast and complete is another advantage. The need to capture all relevant information is constrained by time pressures to reopen traffic lanes, finish demolition of hazardous structures, move objects in a crime scene to seek bloodstains or other evidence. Too, investigators typically revisit a crime scene between 8 and 12 times, according to Francis. Having the digital "scene" on their desktop lets many return visits be made virtually.
Forensic calls can be to a homicide scene, a traffic accident or any other happening that police or private investigators need to document. Forensic projects have five stages, Francis says. On each call the team must (1) prepare for the visit to the scene, (2) document the scene as required by the client, and to their own satisfaction, (3) assemble the data to recreate the scene, then analyze the data, (4) prepare and present the final deliverables, and (5) wait for possible follow-up requests. SPAR 2005 attendees learned what procedures Northway-Photomap has developed for each step.
3D laser scan of auto accident scene
Image courtesy Northway-Photomap Inc.
