Sherlock Holmes's fictional genius for deductive logic helped solve many a mystery with help from nothing more than microscopes and magnifying glasses for technology. Optical technology has now evolved into 3D lasers.
These technologies recreate crime scenes in rich 3D spatial detail, which misses very few pieces of the puzzle. A latter-day Sherlock Holmes would be intrigued by the range of theories that can be virtually tested even when much of the physical evidence is destroyed by criminals.
A case in point was a double-murder in Georgia where the suspect burned down the home of the victim in order to not to leave any trail behind. As it turned out, the case was quickly solved with help from lasers. While the exact details of the case are not known, similar cases have used the depth-sensing capability of lasers to determine the flight path of fleeing criminals. The angle of the bullet and the depth of its penetration inside the body of a victim provide a measure of the distance from where it was fired.
Holmes uses a visual aid in 1887.
Sherlock Holmes had a keen eye for microscopic details that could be pieced together to trace murderers. Most times, telltale details like footprints are missed, or their replicas, typically created with plasters, are imprecise and useless if the suspect disposes of the footwear. Laser technologies create digital impressions which can be circulated instantly to police officers from the cloud. This evidence can be compared when suspects are detained, before that evidence becomes outdated.
Usage of 3D has grown rapidly since its first launch in Chattanooga, Tennessee, in 2010. More than 100 law enforcement agencies have installed Leica Geosystems ScanStations around the country. They are finding that they can reduce the time spent with juries when unanticipated questions are asked by replaying imagery generated by lasers. They can respond with information that was previously unnoticed. Other mobile forensics technologies are also available for use in the field, for example following car accidents.
Juries wrestle with conflicting accounts by witnesses and struggle to reconcile manual forensics that are incomplete or subject to dispute. But they can relive the crime scene when aided by 3D laser imagery, enhanced by photorealistic animations. The narratives of witnesses can be tested by simulating what could possibly be seen from the vantage point of witnesses. The crime scene can be animated to check for the consistency of the case made by the defense or the prosecutor.
One such case involved charges against a member of the police force, alleged to have used excessive force by shooting the driver of a stolen car (who reversed the vehicle after a long chase and crashed into a police car, killing an officer). 3D laser imagery confirmed that the car was reversed at an unusually high speed, as suggested by a skid-mark recreated from a photograph, which pointed to an intent to kill the officer in the car.
The cities of the future are going to encounter increasingly sophisticated criminals adept at covering their tracks. Witness accounts will likely be fuzzier as the witnesses are ever more preoccupied with their worlds and their devices. The prosecutors and the defense sides have learned to be disingenuous, while juries are overwhelmed the details of a case. Forensic science will need a leap like that provided by 3D lasers to cope.