Forensic DNA evidence is critical to solving cases in the illegal trade of plants and animals. Unlike catching a poacher hunting on-site, enforcing such laws that protect endangered species becomes difficult when the evidence is only a product or part of the organism, and is found far from their original source.

The legal trade in animal and plant products is important to the economy of many local communities. However, decreases in effective breeding populations have prompted bans in the trade of certain products. Unfortunately, these bans have not discouraged their illegal trade, particularly where the industry is profitable and the consumers are not adequately educated.

For example, most caviar, comes from sturgeon caught in the Caspian Sea. Catch limits are in place to protect these populations; however, the profit to be made on rare caviar often outweighs the risks of being prosecuted. In many similar cases, the scarcer the commodity, the more they are valued, increasing the profit margin and thwarting efforts to increase population sizes.

Enforcing laws protecting threatened species presents unique challenges not encountered in combating other illegal trade such as drugs or weapons. Many of the products are not easily recognizable, and can be passed off of as those from legal species. Adding to this problem is the fact that animals of the same species may be legal to capture in some regions or countries, but not others. Some animals intended for the pet trade are legal if they are captive bred - although in most cases a wildlife or customs office cannot ascertain their origin.

Before the emergence of wildlife forensics as a law enforcement tool, enforcement was limited to catching poachers or smugglers in possession of easily identifiable products such as endangered plants or tiger skins. However, the application of DNA technology has allowed the identification of parts of organisms. Custom's officers can now take a sample of a shipment of fish or traditional medicine products and determine, using DNA technologies, whether it contains species that are banned from trade, or even from a specific population within a species that is protected by law. Similarly, parentage analysis, which compares DNA profiles of parents to those of offspring, can confirm or refute a pet trader's claim that animals were bred from captive populations.

A number of forensics laboratories have been established specifically to address wildlife genetics issues including:

• U.S. Fish and Wildlife National Wildlife Forensics Laboratory in Ashland, Oregon
• University of Maine, Molecular Forensics Laboratory in Orono, Maine
• Trent University's Wildlife Forensic DNA Lab in Ontario, Canada