goddard: we have to figure out what the victim is in terms of species. it may be legal to kill a certain species or perfectly illegal, depending on its genus and its species. we can analyze the dna of a tree, then we can extract dna from that plank, which is all we need to examine the oils to determine this genus and species. we are the first crime lab ever to have a xylarium, where we use the known samples to identify wood evidence. lancaster: so a xylarium is for wood what a library is for books. it's where we house all the different wood blocks that allow us to look at reference material when we get a new sample. and so, if we get an unknown and we have an idea of what it is, we can build a population based on what we have here. there are wood collections all over the world, and we partner with a lot of them in order to build what you see here. we have probably close to or over 15,000 different wood blocks or slivers in this room, and that really encompasses an incredible portion of commercial woods that are imported into the united states. woman: i'm