TV shows such as CSI have a lot to answer for, showing forensic labs staffed by Hollywood-beautiful people using technologies that simply don't exist.
The truth of forensic investigations is far more complex, and a new Australian invention shows that the real technology in use is even more impressive. Looking like a miniaturised Ghostbusters Proton Pack, it's called the Zebedee and is used to recreate crime and accident scenes with an incredible degree of accuracy.
Developed by the CSIRO over seven years, the laser-scanning technology was initially intended for a different purpose.
Dr Jonathon Roberts, one of its creators, says it was developed so mobile robots could observe the world around them. The device takes 40,000 measurements per second, to a distance of 30 metres, then builds up a detailed map of the environment based on the reflections of the laser.
It is not the first laser scanner in the world, but the portability of the Zebedee allows crime and accident scenes to be captured faster than ever, a crucial factor when scenes deteriorate rapidly due to weather or traffic.
It can take as little as 20 minutes to scan an average scene, which is then used to build a computer recreation accurate to 10 millimetres.
Everything in the crime scene is captured, from empty bullet casings to individual leaves. It's an invaluable aid, says NSW Forensic Services Group Commander, Assistant Commissioner Peter Cotter, helping "investigators and jurors ... understand the context of an incident".
The Zebedee is being used by Queensland Police, but NSW Police has an even more powerful laser scanner in its arsenal.
The HDS7000 is a much larger device, requiring the use of a tripod, but its accuracy is unrivalled.
The $250,000 unit has been used increasingly in the past year, building recreations of scenes accurate to 1 millimetre, detailed enough to capture a single fingernail trimming.
This level of accuracy allows police to zoom in on bullet holes and ricochet points, from which ballistics experts can calculate the trajectory of bullets, without ever visiting the crime scene.
It's paired with a high-definition camera so the scene can be rebuilt as a photorealistic 3D animation, allowing investigators "to walk through" the scene and examine blood spatter and other visual indications that aren't captured through laser scanning alone.
The scanner can be used to capture vehicles involved in a car accident, and the scanned 3D models can then be manipulated on a computer like the pieces of a puzzle to see exactly how the vehicles collided.
The size and accuracy of the HDS7000 means it takes much longer than the Zebedee to get a full scan of the scene, which is why NSW Police is investigating the purchase of hand-held scanners.
Another piece of cutting-edge technology using lasers recently deployed by NSW Police is much smaller – the TruNarc drug analysis device is about the size of a book.
Using a technique called Raman Spectroscopy, this hand-held gadget allows police to identify drugs in minutes, a process that used to take days or weeks.
Before the purchase of these $30,000 scanners, police would have to send samples of seized drugs to labs for testing, which could delay investigations for up to a month. Now they can hold the capsule, pill or bag of powder up against the laser lens and, within a minute, the device identifies the major active ingredient.
Lasers are also helping police to investigate shootings. IBIS, or the Integrated Ballistics Identification System, uses a combination of photography and lasers to measure the striations on fired cartridges and bullets. The striation is the unique fingerprint imprinted on a casing or bullet when fired from a weapon, and IBIS matches cartridges and bullets fired from the same weapon within 15 minutes, a process that used to take months, if not years.
The NSW IBIS system has more than 40,000 cartridges and bullets captured in its system; manually finding a match against so many samples is physically impossible. While IBIS has been in use in NSW for more than a decade, it was recently updated to the version used by the FBI and Interpol. By the end of this year, IBIS will use a secure network to share its database with both of these organisations, making it harder to reuse weapons overseas.
Unlike the jack-of-all-trades seen on crime shows, each of these devices requires extensive training and knowledge.
"CSI portrays a very small number of experts as having an enormous breadth of scientific knowledge," Assistant Commissioner Cotter says. "In any major matter, it is likely that there will be a significant number of subject matter experts involved."
