U.S. flag

An official website of the United States government, Department of Justice.

Combating Transnational Organized Crime by Linking Multiple Large Ivory Seizures to the Same Dealer

NCJ Number
Science Advances Volume: 4 Issue: 9 Dated: September 2018
Date Published
September 2018
11 pages

This article describes the use of the genetic methods of Wasser et al. in enabling law enforcement investigators to identify export cartels that consolidate and ship large volumes of elephant ivory out of Africa.


Wasser et al. developed DNA-based tools that can identify the major poaching hotspots in Africa, which enabled the statistical assignment of the geographic origin of ivory samples to within 300 kilometers of the poaching source. This was done by comparing sample genotypes at 16 microsatellite DNA loci to a comprehensive DNA reference map of elephants assembled from across Africa. Applying this method to representative samples from numerous large ivory seizures enabled Wasser et al., to identify the two largest ivory poaching hotspots in Africa over the past decade. This investigative technique has become important, because most poachers apparently sell their ivory to a pyramid-shaped hierarchy of middlemen, who progressively consolidate the ivory as it moves up the crime chain to the export cartels These cartels are the final consolidators, exporting individual containers filled with multiple metric tons of ivory out of Africa many times each year. The high cost of ammunitions needed to kill elephants on such a large scale suggests that cartels are funding poaching operations that kill the elephants. Individual poachers are difficult for law enforcement officers to identify in the field, because they typically operate in large protected areas with which they are familiar, and they can handle only small amounts of ivory. Thus, it is more cost-effective to identify ivory cartels who pay poachers to kill elephants. Since ivory tusks are shipped in separate containers in relatively small amounts, perhaps only one tusk per container, this article describes the genetic matching of ivory samples in separate seizures between December 2011 and May 2014.

Date Published: September 1, 2018