At a major crime scene such as a murder, detectives record measurements from every conceivable angle so they can attempt to explain scientifically how the crime unfolded.
But when it's time to present their findings to a jury, they often have to verbally explain what actually happened, aided only by two-dimensional photographs, which often do not cut it with juries that demand more visual presentations.
Some call it the "CSI effect," referring to the popular TV shows, but even animations won't always do the trick.
The problem, Berks County Detective Albert Schade III explained (in December) is that police and prosecutors have neither the time nor expertise nor financial resources in most cases to undertake expensive computer modeling.
Schade, a former Reading police officer and evidence technician who works in the forensic service unit of the district attorney's office, claims to have found a solution to this problem.
He discovered that he can use a computer program that can be downloaded for free online to create a detailed 3-D model of a crime scene from the measurements and drawings evidence technicians obtain from an actual scene. Then, with some modifications to gaming software, he can virtually take the viewer into the scene using a computer mouse.
This interactive, 3-D modeling is superior to regular animation, which, like a movie, doesn't give prosecutors the opportunity to change angles, zoom in, or do a flyover, for example.
"If I want to walk a jury through a crime scene I really can't do it with animation because they're all looking through one camera angle," Schade said. "Having an interactive way to walk through things and talk to people while doing it is very helpful."
Schade spent about two years working on his program for 3-D interactive modeling, which he demonstrated Wednesday to local media and the county commissioners at the county agricultural center in Bern Township, where the forensic unit is housed.
He collaborated with two other authors, Elissa St. Clair of the Naval Criminal Investigative Service, and Andy Maloney of FORident Software, on an article "An Introduction to Building 3D Crime Scene Models Using SketchUp," that was published Nov. 20, 2012, in the Journal of the Association for Crime Scene Reconstruction.