The time is apparently coming when law enforcement will be able to track down a suspect based on a strand of hair or some other sample of DNA dropped at a crime scene.

An international scientific team, led by researchers from Pennsylvania State University, is exploring how people's genetic codes influence their facial structures.

Although an individual's sex, skin tone, and eye and hair colors have long been relatively easy to predict through DNA testing, determining specific facial structures through the same method has been much more challenging, Penn State anthropologist Mark Shriver, who led a study on the influence of DNA on facial characteristics, said in a school news release.

Findings of the research were published in the journal PLOS Genetics.

"By jointly modeling sex, genomic ancestry and genotype, the independent effects...on facial features can be uncovered," the researchers wrote in the paper. Also, "by simultaneously modeling facial shape variation as a function of sex and genomic ancestry along with genetic markers in craniofacial candidate genes, the effects of sex and ancestry can be removed from the model thereby providing the ability to extract the effects of individual genes."

Put another way, the researcher has revealed much more about how certain genes and their variations help shape one's face and its features.

"We use DNA to match to an individual or identify an individual, but you can get so much more from DNA," said Shriver in the release. "Currently we can't go from DNA to a face or from a face to DNA, but it should be possible."

To test physical face shape, Shriver and his colleagues looked to populations of mixed West African and European ancestry from the United States, Brazil and Cape Verde.

They placed a grid over 3-D images of the subjects' faces and measured the spatial coordinates of the grid points. They then used statistical calculations to figure out the relationship between the variations in the faces and the effects of sex, genomic ancestry and genes.

"Probably only 5 percent of genes show a difference between populations," said Shriver. "We are using different populations because they have had different environments and different social environments."

Eventually, the researchers think, scientists may be able to approximate the image of a parent from the DNA of a child, or get a better sense of what early human ancestors looked like.

And, of course, members of law enforcement groups could be able to eventually use DNA sampling to create mugshots that predict the identities of victims as well as criminals.