AFP Museum curator Sebastian Spencer with one of the original Polilight machines. Photo: James Coleman.
How many criminals around the world have Canberra to thank for the fact they’re now behind bars? Turns out it’s probably in the hundreds of thousands.
You’ve seen it on nearly every crime-related show: the police rock up to the crime scene, kill the lights and whip out their blue torches to scour for fingerprints, bodily fluids or any other signs of a scuffle that’s hidden under ordinary light.
Nowadays, these blue torches are used in about 98 per cent of real-world crime scene investigations by law enforcement across the world.
Called “Polilight”, they were first used in the 1980s by our own Australian Federal Police (AFP), working with the Australian National University (ANU).
Up close with the Polilight. Photo: James Coleman.
One of the early prototypes, dated to the late 1980s, is held by the AFP Museum in Hume. Seeing it out on a table, it’s clear things have come a long way even since then – it’s an enormous black metal box, with a power cord coming out one side and a type-written note on the front with operating instructions.
And then there’s the bulky separate lens you can screw onto the front to focus – or widen – the light’s beam.
Still, it’s a lot more mobile than what came before.
AFP Museum curator Sebastian Spencer says, for decades, the only way for police to track down a suspect was to dust a crime scene for fingerprints – a process that was as lengthy as it was inaccurate.
It turns out a human’s fingerprint can be up to 99 per cent similar to that of a koala’s.
“How many koalas have committed heinous crimes, we’ll never know,” Sebastian says.
“But also, you wouldn’t want your case to hinge on whether we took your fingerprint correctly, because we never factored in at the time how the paper itself might react to inks and acids and while we might have your 10 fingerprints, we’ve got another 2000 cards with fingerprints to go through.”
A fingerprint dusting kit. Photo: James Coleman.
There was also the portability aspect.
“I can’t bring that crime scene into the laboratory … I’d have to take off floor tiles and doors and take it to the lab.”
Ultraviolet light – and the way it causes many substances like urine, blood and cleaning agents to “fluoresce”, or glow – was a known phenomenon. For instance, everyone expects their white shirt to light up or their eyes to glow under the UV lights in a nightclub.
But up until the AFP in 1981, when the first Polilight was produced by the joint AFP-ANU team, Sebastian says no-one had ever thought to apply it to crime scenes.
A poster explaining how fingerprints are to taken correctly. Photo: James Coleman.
“It was the practical application that was the game changer,” he says.
“It opened up another whole world … a good villain would try to be one step ahead of us and wear gloves but with the UV light, we could pick up a little bit of fabric from the jacket that you didn’t even clock was on the floor, or a strand of hair.
“And even some cleaning agents used to break down the irons and hemoglobins in blood show up, so we can see if an area has been cleaned.
“All these tiny little bits are enough to start the snowball effect and break down the case.”
A second improved version of the Polilight came along in 1985, which debuted at an FBI fingerprint conference in the US the same year. From there, the technology almost immediately took the world by storm.
Pretty much the only change ever since has been in size.
“Just as the first mobile phone was as big as a house, we’ve got ones in our pocket now,” Sebastian says.
The UV Polilight. Photo: James Coleman.
AFP principle forensic scientist Dr Kylie Jones adds that the Polilight undisputedly “changed the game”.
“The innovation helped establish the AFP’s reputation as a global leader in policing science – and gave forensic TV writers a lot of great material,” she says.
There’s now even a street name here in the ACT to celebrate the achievement too – yep, there’s an actual Polilight Street in Dunlop. Probably the safest street in the city.
