On television and in the real world, crime scene investigators analyze human DNA in order to link a suspect to a crime. This DNA could be collected from blood samples, fingerprints, skin and even hair.
The scientific study of human hair is known as trichology. According to the Carolina Biological Supply Company, which supplies science and math education materials to educators across the country, hair “is more resistant to decay than most other body tissues and fluids, thus remaining intact far longer than other evidence. This durability makes hair one of the most frequently found pieces of evidence at crime scenes.”
But, let’s say, hypothetically, hair from your head was found at the scene of a crime you did not commit. That scenario has been posed by online users for years.
In 2014, someone on Reddit asked, “What if someone wearing my donated hair on a wig committed a crime and left behind a strand of my hair....” In a viral post from 2017, a Twitter user said their 12-year-old niece wondered the same thing.
VERIFY viewer Sharon told us she recently saw the same question circulating on Facebook and asked us to find the answer.
Can a hair donor be implicated for a crime the wig recipient commits?
No, a hair donor can’t be implicated for a crime the wig recipient commits. Experts said there are a variety of reasons why, including how wigs are made.
WHAT WE FOUND
Lawrence Kobilinsky, a forensics hair analysis expert at New York City’s John Jay College of Criminal Justice, told VERIFY the average person loses 100 hairs every day.
“You know there’s a saying that, ‘Wherever you’ve been, you leave signs of yourself.’ And I think that’s very true. It’s either DNA, or it’s some form of DNA, and hair is a form of DNA,” Kobilinsky said. “It’s a common form of evidence; it’s important evidence.”
In a statement to VERIFY, the FBI said they have found synthetic wigs and hair extensions at crime scenes – and sometimes those samples include human hairs.
Kobilinsky said there are several important steps investigators take when they find hair samples at a crime scene – they can determine hair length, cut and color by the naked eye, but further testing needs to be done microscopically.
At the microscopic level, an investigator can look at the cellular structure of the hair. This microscopic analysis can really tell someone if they are looking at a strand of human hair, synthetic hair from a wig or human hair that’s been made into a wig.
For instance, the cuticle, or the outer layer of a strand of hair, has scales that overlap one another and protect the inner layer of the hair. Human hair has cuticle scales that are flattened and narrow.
But, when wigs are made, the hair is descaled, which basically means the hair is stripped and conditioned so that each strand is uniform, Kobilinsky said. This strips the hair of any evidence of DNA.
“The bottom line here is finding a wig at a crime scene is not going to fool any criminalist, they’re going to be able to tell right away if [the hair] is from a wig,” Kobilinsky said. “And if it turns out that the perpetrator actually wears a wig, which is quite possible, then you want to be able to do a comparison.”
Hair analysis is a comparative science, which means a sample found at a crime scene must be compared to another hair sample, he said. But, investigators would be able to tell immediately if hair found at a crime scene was from a wig, making it extremely difficult to do a comparison.
In addition to the cuticle, DNA can also be found in the root of the strand. When hair is shed or pulled, the root is typically intact and DNA can be found on the sample.
Human hair used to make wigs and hair extensions are typically formed and cut, so those roots that contain DNA are not usually present. Plus, there is no guarantee that all the hairs in the wig are from the same individual, the FBI said.
“Obtaining DNA from a wig or hair extension would be an unlikely occurrence due to the processing of the hair to make a wig/hair extension,” the FBI said.