Forensic Palynology Offers New Fingerprint for Fighting Crime

...like DNA, pollen and spores are invisible clues at a crime scene that could help convict murderers, thieves, rapists and terrorists.

By Vaughn Bryant and Leanne South

The teenaged girl lay crumpled in the New York cornfield where she had been shot and left to die. Investigating police had no clues to follow. Her pockets were empty and the labels in her clothing had been ripped off. Weeks, months and then years passed as police followed hundreds of leads and searched missing-person reports across the country. Finally, they gave up. Twenty-seven years later, police reopened the case and sent her stored clothing to Texas A&M for forensic pollen testing. The testing did not solve who killed her but did reveal that she probably came from Southern California — probably near San Diego.

Forensic palynology — using pollen to investigate criminal cases — is not new. The United Kingdom, New Zealand, Australia, and parts of continental Europe and Canada routinely use it. However, this technique is rarely used in the United States, where only a few experts exist. One of those is Vaughn Bryant, an anthropologist at Texas A&M University.

Honey of a job provides training for forensic analysis

Bryant’s interest in forensic palynology began in the mid-1970s when the U.S. Department of Agriculture asked him to analyze honey samples. A government subsidy program bought domestic honey, but officials suspected that some beekeepers were selling imported honey to the subsidy program. Today he still analyzes honey to help ensure that importers are getting the types and quality of honey they pay for. During this 30-year period, Bryant has identified more than 1,500 samples and developed a keen knowledge of the regional pollen prints found in the United States, Canada and Mexico.

“Get me a piece of Osama bin Laden’s clothing and the pollen will tell me where he is hiding.”

-Dr. Vaughn Bryant

Pollen: a good crime scene marker

The world has about 500,000 different plant species, each producing a unique type of pollen or spore. Many produce millions of pollen grains or spores and disperse them in the wind. Others rely on insects, birds or mammals to complete the pollination process. Each region has a unique combination of plants, so the pollen and spores form unique “pollen prints” for each region, similar to fingerprints in humans. When someone commits a crime, the criminal usually picks up pollen evidence on clothing, on the criminal’s vehicle or on anything the criminal used at the crime scene. Later, the pollen evidence from those objects or the criminal can link the criminal to the crime scene.

A scientist trained in botany or palynology also will know the production life cycle and dispersion patterns of the various plants. During a criminal investigation in which pollen samples have been extracted, the scientist can help determine the specific locale of a crime, the time of year it took place and whether evidence has been removed from its original location.

Since the 1990s some law enforcement officers have asked for Bryant’s help, which he is interested in doing, but that interest also puts a strain on his day job as a professor at Texas A&M. “I continue to do forensics because it is important, and I want to draw attention to the need and benefits of pollen evidence,” Bryant says. “Currently, pollen evidence is being used in Europe to fight terrorism and convict those responsible for acts of genocide.”

Key to 21st century crime and crime fighting

Bryant believes that the global threats presented through illicit drugs and terrorism make finding new and more effective investigative tools for law enforcement imperative. The scientific community has the experience, the extensive pollen samples, the equipment for collecting and analyzing samples and the capability to train others in the field, but U.S. law enforcement still has not embraced this tool. Bryant says it will probably take a high-profile case to grab their attention. “Get me a piece of Osama bin Laden’s clothing and the pollen will tell me where he is hiding.” 

Liberal Arts College Relations Intern Blair Williamson contributed to this story.