A genetics company called Parabon Nanolabs recently analyzed some remnants of DNA from a crime scene — not for fingerprints, but to create a digital likeness of the alleged criminal's face, Science News reported.

Then, they sold the image (shown below) to the police:

Using DNA to create images of stranger's faces

This isn't the first time the company has used genetic remnants to create images of stranger's faces.

Back in May, the same company teamed up with a Hong Kong ad agency to shame local litterbugs for polluting the streets.

Using the DNA left behind on gum and cigarettes, Parabon zeroed-in on genes that code for physical traits like hair and eye color. Then, they drafted computer-generated sketches of each polluter's face, printed them out on giant wanted posters, and pasted the sketches on billboards throughout the city:

The science of creating a face from scraps

Unbenownst to many, the science behind the idea — of using DNA to predict a face — has existed for years.

In 2012, New York City-based artist Heather Dewey-Hagborg used the same technology to make sculptures of complete strangers using only the tiny bits of DNA left on discarded cigarettes and chewing gum that she collected from the streets of New York.

Each piece of trash that Dewey-Hagborg collected was rich in genetic data, typically in the form of DNA encased in dried spit or inside pieces of hair and skin.

To isolate that DNA, she did a simple lab procedure (so simple, I've done it myself) at a small community lab in Brooklyn. Then, using a computer code she wrote based on a face model designed by researchers at the University of Basel in Switzerland and used that to comb through all the DNA and pick out only the genes that coded for physical traits, like hair and eye color.

Her exhibit, called "Stranger Visions," has been shown in galleries across the world. Here's an image of Dewey-Hagborg with one of her three-dimensional works of art, which she created with the same type of technology:

Heather Dewey-Hagborg looking at one of her sculptures at an exhibit. Biogenfutures/Vimeo

In addition to hair and eye color, these bits of our DNA dictates the shade of our skin, the width of our noses, and the distance between our eyes, but they can’t tell how old or physically fit we are, for example.

Likenesses, not exact replicas

While the masks aren't exact likenesses of the people they're based on, they do display what Dewey-Hagborg calls a "family resemblance."

The same rule applies to the images Parabon creates. They aren't exact likenesses, Ellen Greytak, Parabon’s bioinformatics director, told Science News. “We work with law enforcement to give them an idea of who they should be looking for.”

As vague as it is, a general idea is all the current science can guarantee.

That's because each of us has 3 billion chemical base pairs of DNA — the letters A, C, G, and T — that altogether make us who we are. One method of analyzing all of these genes is looking only at single letter variations that've been linked to specific traits like hair and eye color, susceptibility to certain diseases, and ancestry. This method of DNA analysis is called SNP (pronounced "snip") sequencing.

The technique is far better at predicting certain traits than others. Scientists can use it to predict blue and brown eye color and red hair color, for example, with pretty striking accuracy. But blonde hair is much trickier, and things like height and face shape are another matter entirely.