Unraveling mysteries: the role of forensic science in conservation and criminal justice

Forensic science is where meticulous investigation meets groundbreaking technology. It unravels the complexities of human and animal-borne biological evidence to solve criminal and civil cases. Forensic research transcends the boundaries of anthropology, biology/DNA analysis, chemistry, computational/digital, engineering, odontology, pathology, and toxicology, from solving cases to building comprehensive reference human and non-human DNA databases for identification, comparisons and statistical estimations.

In this insightful interview, Professor Sreetharan Kanthaswamy, a leading expert at Arizona State University’s School of Interdisciplinary Forensics, delves into the dynamic world of forensic DNA analysis. He shares how his pioneering work in wildlife genetics evolved into using DNA evidence to crack criminal cases, emphasizing the importance of collaboration, innovation, and ethical diligence. Whether identifying trafficked orangutans or solving crimes with animal and human evidence, Professor Kanthaswamy’s expertise highlights the profound impact of forensic science on our criminal justice system and our wildlife conservation efforts.

This conversation illuminates the realities of the field, demystifying the romanticized TV portrayals and uncovering the rigorous dedication required to advance forensic practices.

Question: How did you first become interested in forensic science?

Answer: Genetics fascinated me initially, and I began working on various DNA analysis techniques. My journey started in wildlife forensics, specifically with orangutans in Borneo. I developed genetic markers to understand their social structures, determine paternity, and estimate kinship levels. Findings from this research, including the DNA markers I developed and the genetic databases I built, eventually contributed to combat wildlife smuggling.

Q: Did you get to work directly with orangutans?
A: Yes, during my PhD and postdoctoral research, I collected blood and hair samples from wild orangutan populations and zoo animals. I found the orangutan to be highly intelligent and curious. I remember visiting a rehabilitation center where one approached us to inspect our bags as if working for TSA. It was heartwarming to see how they share behavioral traits with humans; despite reflecting different evolutionary backgrounds and a genetic divergence that lasted millions of years, there was a shared kindred.

Q: You mentioned their genetic similarity to humans. Can you elaborate?
A: Humans and orangutans share about 97% of their DNA, a little lower than the 99% shared similarity between humans and chimpanzees, our closest relatives among the great apes. The small percentage of differences influences traits unique to each species.

Q: How does this work connect to forensic science?
A:  Genetic markers help identify individual humans or animals uniquely, understand their social structures, and trace their ancestral origins, just like 23andMe or Ancestry.com. In animal forensics, genetic markers can localize an animal's geographic origin, identify its species, determine its parentage, or individualize it. We’ve used DNA evidence to connect suspects to crime scenes through pet hair to link a human suspect to a victim or crime scene or address cases of meat adulteration. We have used DNA evidence from wild animals to tackle trafficking and bolster conservation efforts, which are crucial for protecting our endangered wildlife species.  In human cases, bio-evidence like hair or saliva can connect human suspects, victims, or the location of the crime.

Q: You’ve also worked on DNA databases. Can you share more about that?
A: Yes, I helped build one of the largest national DNA databases for dogs. This database was unique because it was one of the first to include many mixed-breed dogs, which used to be largely absent from many databases, especially those based on research studies. Most people own mixed-breed dogs; therefore, evidence from these animals is commonplace in crime scenes. Understanding mixed-breed dogs' genetic composition and diversity was vital for accurate representation when calculating match probabilities and other statistical estimates.

As we studied dog breeds to develop their reference databases, we made some interesting discoveries. For instance, poodles are genetically closer to wolves than German Shepherds, even though the poodles look less wolf-like compared to the Shepards.

My collaborators and I developed the most comprehensive Native American DNA reference databases for forensic use. This effort stemmed from our research on tribal DNA and ethnohistoric evidence, which revealed that the Native American population reference databases used in forensic cases at that time did not adequately represent their genetic diversity. The databases of that time frame underestimated the rich genetic background of these people.

Q: How do you use these databases in forensic investigations?
A: Comprehensive reference human and non-human DNA databases are highly valuable for identification, comparisons, and generating statistical estimations.

Q: What advice would you give students interested in forensic science?
A: Our students must realize that forensic science is an interdisciplinary field that integrates biology, chemistry, and other sciences to reconstruct crime scenes effectively. Therefore, they need to have a sound scientific background to be successful forensic analysts.

Forensic science requires patience, collaboration, and meticulous attention to detail. It’s not like TV shows where crimes are solved in 45 minutes. Students should stay updated on the latest technologies and approaches and embrace the hard work and dedication needed for the field.

Q: What’s the biggest challenge in forensic science today?
A: One major issue is managing forensic case backlogs, especially in sexual assault cases. Another is ensuring forensic scientists stay proficient with advancements and use quality standards to ensure the accuracy and reliability of their work. Mistakes can occur when professionals rush or rely on outdated methods.

Q: Where can people learn more about your work or forensics in general?
A: Interested individuals can visit the Arizona State University School of Interdisciplinary Forensics website. It’s a great resource to explore programs and research opportunities.

Note: Listen to the full podcast on Finding Genius Podcast.