Accurately identifying DNADNA, or Deoxyribonucleic Acid, is the genetic material found in cells, composed of a double helix structure. It serves as the genetic blueprint for all living organisms. at crime scenes is pivotal yet fraught with challenges. Traditional DNA analysis requires sophisticated equipment, specialized facilities, and highly trained personnel, often making it a costly and complex endeavor. Addressing these hurdles, researchers at the University of New Hampshire (UNH) have made a groundbreaking advancement by developing a new, cost-effective test for analyzing forensic touch DNA. This innovative approach revolutionizes forensic investigations, offering a simpler and more accessible method for identifying DNA left behind through mere contact.
The Study’s Genesis and Methodology
Samantha McCrane, an anthropology lecturer and co-director of UNH’s Forensic AnthropologyForensic anthropology is a special sub-field of physical anthropology (the study of human remains) that involves applying skeletal analysis and techniques in archaeology to solving criminal cases. Identification and Recovery (FAIR) Lab, spearheaded the study, which was recently featured in the Journal of Forensic Sciences. The research focused on a more accessible and affordable sequencing method, qPCR, which significantly differs from more traditional, complex DNA analysis techniques.
The researchers orchestrated a series of trials involving male and female volunteers to validate their new method. These trials were designed to test the protocol’s ability to identify DNA from primary contact (the person who may have committed the crime) and secondary DNA inadvertently transferred through touch. In one experiment, a male participant held a gun grip for thirty seconds, followed by a female who touched a coffee cup. The subsequent DNA analysis of these items offered insights into the method’s efficacy in distinguishing between direct and indirect DNA transfers.
Findings and Implications
The findings were illuminating. Male and female DNA was detected on the gun grip in 71% of the trials, indicating primary transfer. Male DNA was found on the female’s hand in 50% of the cases, representing secondary transfer. Notably, male DNA appeared on the coffee mug in 27% of the trials, demonstrating tertiary or third-level transfer. These results underscore the method’s potential to differentiate between direct and indirect DNA contact, a capability of immense value in forensic science.
McCrane highlighted a critical concern: the possibility of transfer DNA implicating individuals who had never physically interacted with specific items or victims at a crime scene. This phenomenon has led to wrongful charges in the past, underscoring the importance of accurate DNA analysis in protecting the innocent.
Beyond the Research
The study also explored variables such as age, ethnicity, and skin conditions to determine their impact on DNA transfer rates. The findings showed no significant association between these factors and the likelihood of primary DNA transfer, adding another layer of reliability to the test.
As the field of forensic science continues to evolve, the need for more research into DNA transfer is evident. The UNH team’s work contributes valuable data to this underexplored area, paving the way for further studies that could refine our understanding of DNA transfer dynamics. With the development of this inexpensive protocol, the door is now open for larger sample sizes and more comprehensive investigations.
Conclusion
The University of New Hampshire’s innovative approach to touch DNA analysis heralds a new era in forensic investigations. By simplifying DNA identification and making it more accessible, this method can enhance the accuracy of crime scene analysis and protect the innocent from wrongful accusations. As forensic science progresses, McCrane and her team at the FAIR Lab’s contributions underscore the importance of innovation in pursuing justice.
Republished courtesy of the University of New Hampshire.
Paper Reference: McCrane, S. M., & Mulligan, C. J. (2024). An innovative transfer DNA experimental design and qPCR assay to identify primary, secondary, and tertiary DNA transfer. Journal of Forensic Sciences, 69(2), 618-630. https://doi.org/10.1111/1556-4029.15444
