“Miss Scarlet in the dining room with the candlestick” is a well recognized quote from a sleuthing parlor game. Television mysteries and kids’ amateur detective kits are all testimony to our society’s fascination with tracking culprits. Everyone knows that dusting for fingerprints is often one of the first things professional crime solvers do at a crime scene.
The uniqueness of fingerprints as a reliable means to identify individuals was recognized as early as ancient Babylonian civilization, when imprints were used to seal business transactions on clay tablets. But it wasn’t until 1888 that criminal detection methods were radically altered when the Englishman Sir Francis Galton published a classification system in his book “Fingerprints”. Galton calculated the odds of finding two people with identical fingerprints as being 1 in 64 billion.
Criminals have since evolved their attempts to elude the law by wearing gloves of all kinds when they deliberately set out on a “job”. Latex gloves have in recent years become a favorite of this set because of the gloves’ fit and tactile sensitivity. And when their malicious task is completed, the gloves are often tossed near the scene.
Fortunately, it is quite possible to obtain fingerprints from the gloves themselves at this point. They are found left either on the outside from the criminal’s donning or stripping of the glove or on the interior of a tightly fitted glove when it is turned inside out. A pair of latex gloved hands, if tightly fitted, may even leave a print on an exterior surface. After the latex is worn for a while, warming and conforming to the fingers, and the criminal touches any oily surface (something as simple as rubbing one’s neck), a detectable fingerprint could conceivably transfer to objects.
But there is a new “fingerprint” being developed for the detective’s arsenal that further complicates the criminal’s effort to escape identification. Gloves may shortly be of less value than ever to hide one’s identity. Bacteria analysis is being closely looked at as a means to zero in on suspects, according to a report from the National Academy of Sciences. Apparently, humans host blends of bacteria colonies on their hands of which only 13% are ever present on any two individuals.
About 150 bacteria species are present on a person’s hand and can trail to fabrics and other materials at a crime scene. It is possible to successfully trace this personalized bacteria 12 hours or more after it has been deposited on surfaces. According to a recent Associated Press report, this developing forensic tool is so cutting edge that this type of scientific analysis was not possible even two years ago.
Perhaps with the advent of this news, surgical scrub techniques will soon extend beyond the medical world to the domain of crooks who once thought latex gloves were adequate for keeping the law off their trail. However, it seems fairly unlikely that a “dirty rat” pawing through a domestic burglary or worse would be very successful in keeping his germs to himself.