A professional who applies scientific principles to analysis, identification, and classification of mechanical devices, chemical and physical substances, materials, liquids, or other physical evidence related to criminology, law enforcement, or investigative work. Responsibilities include:

• Searches for, collects, photographs, and preserves evidence.
• Performs variety of analytical examinations, utilizing chemistry, physics, mechanics, and other sciences.
• Analyzes items, such as paint, glass, printed matter, paper, ink, fabric, dust, dirt, gases, or other substances, using spectroscope, microscope, infrared and ultraviolet light, microphotography, gas chromatograph, or other recording, measuring, or testing instruments.
• Identifies hair, skin, tissue, blood, bones, or human organs.
• Examines and classifies explosives, firearms, bullets, shells, and other weapons.
• Interprets laboratory findings relative to drugs, poisons, narcotics, alcohol, or other compounds ingested or injected into body.
• Reconstructs crime scene, preserving marks or impressions made by shoes, tires, or other objects by plaster or moulage casts.
• Prepares reports or presentations of findings, methods, and techniques used to support conclusions, and prepares results for court or other formal hearings.
• May testify as expert witness on evidence or crime laboratory techniques.
• Confers with experts in such specialties as ballistics, fingerprinting, handwriting, documents, electronics, metallurgy, biochemistry, medicine, or others.