Did you know that the forensic evidence technique of hair analysis (called trichology) can be used for horses?
Many of you have seen criminal shows such as CSI, where cases are solved by the discovery of a fingerprint at the scene of a crime or saliva on the edge of a cup. Forensic science is a technique of comparing evidence at the scene of a crime to either the defendant, plaintiff, or related person. DNA testing is lauded as the most reliable forensic technique. The other techniques include firearm and tool mark analysis, bite mark comparisons, and handwriting identification, among others. All forensic evidence, save DNA, has been criticized as a "soft" science and is too subjective, unreliable, and misleading to the jury, and therefore should not be used as evidence in a civil or criminal case. A famous decision, colloquially referred to as Daubert, permits most forensic evidence into court, however, there are increasing limitations on how an expert may describe the evidence. For example, a forensic expert must say it is "ballistic certainty" that the forensic evidence is valid, and cannot say that it is 100% a match.
Background aside, let's get to the horses.
Say, for example, 100 California horses were stolen last year, one of them is your prized and highly valuable warmblood. Police receive a warrant to search a deserted barn down a dark, backwoods road near the California and Oregon border. Upon arrival the barn has been hastily deserted. The police find different tools used to mutilate the appearance of horses: hair dyes, heat tools to burn white Appaloosa spots onto monochromatic hides, etc. The police search carefully and find two long strands of hair caught in the splinters of a wooden stall door and they take the hair into evidence. Could the hair be proof that your horse was in the rustler's hideout?
Provide samples of hair from your horse (check your tail brush!), then call in the hair examiners, and providing that DNA testing is unavailable or too expensive, the hairs would be examined under a microscope for comparison. From an exclusionary perspective, we can immediately know that the long, black strands taken from the deserted barn do NOT belong to your horse.... if your horse is a palomino with a pure flaxen mane and tail.
From an inclusionary perspective, the hair taken from the deserted barn isn't very helpful- the long, black strands could possibly belong to your horse if your horse has a long, black tail, but it could also belong to the 99 other stolen horses with long, black tails. Hair analysis is too imprecise to pinpoint just one horse as a source (though some examiners claim they can at least determine the breed of dog when a dog hair is found).
As always there are exceptions, such as is if you had medicated your horse with a substance that could then be tested and detected in the hair found at the deserted barn. And while trichology may be unreliable with proving a match between two hair samples, it can help reveal evidence of the crime, such as if the hair was pulled out or fell out naturally, if the hair had been cut or burned.
I did not research to see if there has ever been a reported opinion involving forensic hair analysis on horse hair, and I imagine it's highly unlikely that there would be, since typically there are myriad amounts of other, and more reliable, evidence to solve a crime. But if you want to do some basic sleuthing around your barn, perhaps to see which horse ate the grain in your equine's stall while you were out riding, check around for some strands of hair and see if you can find the culprit!
My horse Lux at a prior barn
For serious matters, as I always recommend, contact your local equine attorney!