Forensic palynology is a branch of botany which focuses on using pollen as trace evidence to link individuals or objects to a crime

This federal Project Grant award of $120,000.00 was provided by the National Institute of Justice (NIJ) under the NIJ Research, Evaluation, and Development Project Grants program (CFDA 16.560). The grant supports the development of a combined chemical and molecular approach to improve forensic pollen analysis for use as trace evidence in criminal investigations.

The project aims to create a library of unique lipid profiles and DNA markers for different plant species, allowing for rapid, high-throughput, and non-destructive identification of pollen samples. This will help address challenges with traditional microscopic pollen analysis, such as the tedious nature of the process, lack of trained palynologists, and low evidentiary value in court. The research will involve collecting real pollen samples over a two-year period to determine if the molecular profiles change over time. The completed library and raw data will be made freely available online to support broader adoption of this innovative forensic technique.

IT relies on the assumption that geographical regions have unique flora and pollen assemblages, allowing for investigators to pinpoint when and where a person has been. Despite the first reported use occurring in 1959, forensic palynology has been heavily underutilized since due to the tedious nature of traditional microscopic pollen analysis, a lack of trained palynologists, and the low evidentiary value of pollen in court. To alleviate these issues, an orthogonal chemical analysis of pollen using lipid profiling and DNA barcoding strategies is presented here. Different plant species have unique chemical profiles which can be used like fingerprints for identification purposes. A single non-destructive extraction is performed to isolate pollen coat lipids and DNA contained within the grain. Lipid extracts are analyzed using liquid chromatography-mass spectrometry and annotated using MS/MS databases. Three highly variable genetic markers, rbcl, matk, and ITS2, are targeted using species-specific primers and monitored using quantitative polymerase chain reaction (QPCR). A library containing the unique lipid profiles and primers for each species will be created and used as a reference for identification of unknown samples. Real pollen samples will be collected from the same plants over a two-year period to determine changes (if any) to the molecular profile. Lastly, the completed library and raw data will be accessible to interested parties using freely available online repositories. This combined molecular approach aims to improve forensic pollen analysis by providing an objective, high-throughput, and rapid method for pollen identification. The techniques used can be easily integrated with instrumentation found in most crime labs, and the non-destructive nature of the extraction allows for complementary microscopic analysis of the grains. Additionally, the orthogonal approach greatly improves the evidential weighting of forensic pollen analysis by limiting errors that may arise when either technique is used independently. CA/NCF