The man above isn’t some sort of weird vampire, mutant, or other fictional character from a sci-fi/fantasy universe. He’s an alleged car thief. His name is Yafet Askale and he was arrested in the UK in September of 2013 after a successful sting operation. Authorities had suspected Askale of engaging in criminal behavior prior to this particular arrest — they had found stolen property in his possession which they used to convict him of theft earlier. But this time, one could say they caught him red-handed — or, in actuality, they caught him green-faced.
That’s because he has the car’s DNA all over his face.
In the 1990s, a pair of brothers — Phil and Mike Cleary — went into business together. Mike was a chemist and Phil a retired police officer, and together, the developed something called SmartWater. Wikipedia calls it a “forensic asset market” which sounds like something out of the CSI family of TV shows. (In reality, the reverse is true. CSI: New York used SmartWater in a plot point in an episode which debuted in 2008.)
SmartWater — not to be confused with the bottled water of the same name — is a non-hazardous liquid which, once it hits a surface, remains there for a long time, but is invisible under normal light. When someone exposes the item or area to UV light, though, the SmartWater residue shines through, as seen above. In the case of Yafet Askale, when he went to steal the car, a trap inside of it sprayed him with the SmartWater, resulting in the green glow seen on the picture.
But that’s not enough to convict a person of a crime — there are many ways that people could get a faceful of UV-visible liquid, and not all of those ways are criminal in nature. SmartWater goes one important step further. The dye is embedded with a unique identification number. That number is hidden in the patterns shown under the UV light. The item the criminal tried to steal or the area he or she tried to invade is, literally, written all over his or her face.
Of course, booby trapping one’s belongings is expensive and, in some cases, illegal, so this use of SmartWater isn’t all that common. But that’s OK because that’s also not its intended use. The Cleary brothers market SmartWater as a license plate for all your belongings — if you dunk your valuables in this stuff (those that aren’t damaged by liquids, that is), the items become imprinted with your SmartWater ID. If those items are later stolen and recovered by police, the authorities can quickly grab the ID from the item and run it through the SmartWater database. You’ll get your stuff back and the thief will likely go to jail. One British municipality was even working with pawn shop owners, encouraging them to scan peddled goods under ultraviolet light, just to make sure they’re not already spoken for.
And as a bonus, local law enforcement agencies have taken to encoding municipal property with SmartWater and then telling everyone who will listen to beware. (Here’s a sign warning would-be thieves that SmartWater has been applied in the area.) This has been a successful deterrent of crime; one area reported a 94% drop in burglaries during the first six months of a 100-household pilot program. The Telegraph, in reporting Askale’s story, echoed the same sentiment — residents were given free SmartWater by local law enforcement, “which has led to reductions in burglary and street robbery and 80 and 40 percent respectively,” per the newspaper.
From the Archives: On the Juice: The thief who covered himself in invisible ink. Kind of.
Related: The Goop. Not SmartWater, but similar-ish with a better name.