Asian carp leave a trail of DNA just like criminals at a crime scene. Like the forensic scientists who use DNA technology to identify criminals and take them off the streets, fish biologists are using the same technique to detect Asian carp to keep them from causing mayhem in the Great Lakes. At the heart of DNA evidence is the biological molecule which serves as an instruction manual and blueprint for every living thing. Scientists can obtain enough DNA information from just a few cells to identify crime suspects. The same holds true for invasive intruders like Asian carp. Scientists use “environmental DNA” (eDNA) when they can’t see the organisms they suspect are present.