Lab scientist at work. Credit: USFWS

WELCOME SCIENCE PROFESSIONALS

The information in this section is designed for professional scientists. For more general information, please visit Students & Educators.

Forensic Science can be defined as the application of science to criminal laws that are enforced by police agencies in a criminal justice system.

The role of the National Fish and Wildlife Forensics Laboratory is to provide forensic assistance to the Office of Law Enforcement (OLE) of the Fish and Wildlife Service (FWS). OLE is composed of Special Agents and Wildlife Inspectors who enforce the criminal laws and U.S. Statutes that protect threatened and endangered species.

The Office of Law Enforcement of the Fish and Wildlife Service is primarily focused on compliance with criminal law — law that deals with crimes and their punishments. The Lab seldom works on non-federal cases such as state poaching violations, or non-wildlife cases like animal abuse or food contamination.

The analytical assistance provided by the staff at the National Fish and Wildlife Forensic Laboratory can be grouped into four major categories (explained below):

1. Crime scene investigations
2. Cause of death determinations
3. Class character analysis (such as species identification or chemical analysis)
4. Individualization analysis

In forensic science it is of particular importance to distinguish between class character vs. individual analysis.

Crime Scene Investigations
The role of the forensic scientists at a crime scene is to

1. search and locate the evidence
2. protect and secure the evidence
3. document the scene and create a map illustrating the location of the evidence
4. photograph the evidence of interest
5. collect the evidence and preserve the items so that its information is not destroyed by either carelessness or degradation
6. commence a chain of custody of the evidence items

This process is followed regardless of whether the crime scene is an isolated beach in Alaska, or a business computer in Manhattan.

Cause of death determinations
The role of the forensic scientists when the evidence is a carcass is to determine cause of death and manner of death. In the Lab this is done only by the Pathology unit.

Class character analysis
Species are traditionally defined by a suite of morphological characters in conjunction with geographical source information.  To give an oversimplified example, if a large mammal’s provenance is Africa and phenotypically it exhibits big ears, long trunk and ivory tusks, then it can be concluded to be an African elephant (Loxodonta africana) as opposed to an Asian elephant (Elephas maximus).

Conversely if the evidence item received in the Lab is an ivory carving seized in a Baltimore boutique, and the only diagnostic morphological characters are Schreger lines, then the assignment of species source becomes more challenging.  In this example the report would conclude Proboscidean origin of unknown species. Lacking a geographical point of origin or additional identification clues (such as uncarved skeletal elements, DNA, or protein markers), the examiner would only be able to establish identity at a higher taxonomic level; in this case the Order Proboscidea, which includes all elephants.

These two examples illustrate the process of class character analysis, which can be defined as the documentation of a suite of morphological, or genetic, or chemical characteristics which provide the basis for identifying the evidence as a member of a particular category or class.  Examples of “class” can include various taxonomic categories, such as family, genus, and species, as well as molecules (e.g., DDT) and physical objects (e.g., a 9 mm. cartridge casing).

In the Lab class character analysis is done by all the analytical units.

In many wildlife crime investigations, class category analysis provides the needed proof that a violation has occurred, for example by documenting the presence of a protected species or a prohibited chemical.  However, in some cases, further individualization analysis is required.

Individualization analysis
The end point of many OLE cases is to connect a suspect with the crime scene and the victim.  For example, suppose

• the victim (say, a wolf) is found dead at the crime scene
  (links victim and crime scene)
• a suspect’s fingerprints are found at the crime scene
  (links suspect and crime scene)
• the victim’s blood has stained the suspect’s clothes
  (links suspect and victim)

Therefore individual characters (DNA extracted from blood and latent prints recovered at the scene) provide the basis for identity and linkage between victim suspect and crime scene. While class character analysis can demonstrate that the victim is a gray wolf (Canis lupus), individualization analysis is needed to prove that the blood of this particular gray wolf (the victim) is on the suspect’s clothes.

This diagram shows the relationship between VICTIM, SUSPECT, and CRIME SCENE. The VICTIM is linked to the SUSPECT via blood, the SUSPECT to the CRIME SCENE via latent prints, and the CRIME SCENE to the VICTIM via the carcass.

The role and capabilities of each analytical unit at the Forensics Lab are explained in the Science Team sections: Chemistry, Criminalistics, Genetics, Morphology, Pathology, and Digital Evidence.

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