Linking suspects to an illegally felled incense tree (Aquilaria sinensis) using DNA forensics

Incense trees (Aquilaria sinensis) are illegally harvested across Asia due to the high market value of the agarwood they produce. This problem is particularly prevalent in Hong Kong, where government agencies are actively focused on reducing illegal harvesting by finding new means of deterrence and actively prosecuting criminal suspects. We conducted the first case study on incense trees in Hong Kong, where plant materials from criminal suspects' clothing were matched to an illegally harvested source tree using Sanger and whole genome resequencing approaches. We identified several plant particles collected from clothing of suspects to be from incense trees and traced them back to a specific illegally harvested tree. This evidence led to the prosecution of nine suspects who were sentenced to 30-50 months in jail under the Organized and Serious Crimes Ordinance (OSCO) in Hong Kong. This was one of the first times OSCO was used in illegal wildlife trade prosecution in Hong Kong, leading to 25% longer sentences. The result demonstrates that even small, aged and poorly preserved wood particulates can yield enough genomic DNA for whole genome analyses to be used as forensic evidence to support the prosecution of criminal suspects.