New test helps law enforcement predict criminal’s age based on teeth samples

September 16, 2015

Criminals be warned: Leaving a tooth fragment at a crime scene could be your undoing. A new test lets police determine important identifying information about suspected perpetrators from tooth samples.

DNA from blood or tissue samples has long been used to help identify criminals by helping to establish sex, familial connections and other markers. Now, DNA from tooth samples can help law enforcement narrow the pool of suspects even further. Forensic biomedical scientists from KU Leuven in Belgium have developed a test that can predict a perpetrator’s age based on blood or teeth samples.

More we can learn from teeth: Teeth reveal link between iron levels in infant formula, Parkinson's disease

As humans age, changes occur in tissue and organs in a process that is regulated by DNA. This aging process is also embedded in DNA methylation markers, offering a blueprint that enables researchers to predict age with relative accuracy.

Professor Bram Bekaert from the KU Leuven Forensic Biomedical Sciences Unit, one of the researchers conducting the study, explained, “As we grow older, some genes are switched on, while others are switched off. This process is partly regulated by methylation, whereby methyl groups are added to our DNA. In specific locations, genes with high methylation levels are deactivated.”

Using a set of four age-associated DNA methylation markers, Professor Bekaert and his colleagues were able to predict an individual’s age with astonishing accuracy. The study analyzed 29 teeth taken from individuals ranging in age from 19 to 70 years, and correctly identified their age with a margin error of just 4.86 years.

Researchers also took blood samples from 206 individuals ranging in age from 0 to 91 years. The margin of error for the blood samples was 3.75 years. The study uncovered no difference in accuracy in samples obtained from deceased or living individuals or between the two sexes.

In addition to being extremely valuable to law enforcement for tracking down living criminals, the research can also help narrow age range in deceased bodies to help identify human remains.

Analysis of teeth for identification purposes is nothing new: Archaeologists often rely on the analysis of teeth to learn about the lives of past people. In addition to age, teeth can tell researchers a lot about individuals’ diets, links between ancestral populations and nutritional and disease stress during childhood.

The full study, “Improved age determination of blood and teeth samples using a selected set of DNA methylation markers,” was published in the journal Epigenetics on August 17, 2015.

Want to read about how some real-life foolhardy criminals were busted by their teeth? Check out these ridiculous crimes.