CRIMINALISTS ARE FORENSIC SCIENTISTS, RESPONSIBLE FOR EXAMINING MANY TYPES OF EVIDENCE BY ANALYTIC MEANS. THEY IDENTIFY, QUANTIFY, DOCUMENT, AND INTERPRET THE EVIDENCE. THEIR WORK IS DONE IN A CENTER FOR CRIMINALISTIC INVESTIGATION REFERRED TO AS A CRIMINALISTICS LABORATORY, CENTER FOR FORENSIC SCIENCES, CRIME LABORATORY, OR PUBLIC SAFETY DEPARTMENT LABORATORY. DEPARTMENTS INCLUDED WITHIN SUCH A FACILITY FOCUS ON SPECIFIC AREAS OF INVESTIGATION. MANY CRIME LABORATORIES MAINTAIN SPECIAL CHEMISTRY, SEROLOGY, GEOLOGY, BOTANY, METALLURGY, PHYSICS, PHOTOGRAPHY, MICROSCOPY, AND FIREARMS AND TOOL MARKS SECTIONS. THE BIOLOGY OR SEROLOGY SECTION ANALYZES STAINED SURFACES TO DETERMINE STAIN SOURCES; BLOOD, SALIVA, AND TOBACCO ARE SUBSTANCES COMMONLY ANALYZED. MATERIAL TRANSFERED BETWEEN PARTICIPANTS IN A CRIME IS ALSO INVESTIGATED, E.G., HAIR FIBER OR SKIN OF AN ASSAILANT TO A VICTIM. THE FIREARMS AND TOOL MARKS SECTION RECEIVES MUCH OF THE LABORATORY CASELOAD. TOOL MARKS EXAMINATION INVOLVES EVIDENCE LEFT BY PRYING TOOLS, SUCH AS A SCREWDRIVER ON A WINDOW FRAME. THE FIREARMS EXAMINER DETERMINES WEAPON TYPE AND THE TIME, DISTANCE AND DIRECTION OF FIRING. THE CHEMISTRY SECTION FOCUSES ON SUBSTANCE ANALYSIS FOR SUSPECTED DRUGS AND ALCOHOL. THE PHYSICAL EVIDENCE ANALYSTS TRACE SUCH EVIDENCE AS PAINT CHIPS, SOIL, AND GLASS USING BINOCULAR POLAR MICROSCOPES. THE PHOTOGRAPHY SECTION DOCUMENTS EVIDENCE TAKEN AT THE CRIME SCENE. THE IDENTIFICATION SECTION CONTAINS FILES AND EQUIPMENT FOR FINGERPRINTS AND PHOTOGRAPHIC IDENTIFICATION, AS WELL AS COMPOSITE DRAWING KITS. MOST CRIMINALISTS ARE LAW ENFORCEMENT OFFICERS EXPERIENCED IN INVESTIGATIVE WORK, OR THEY ARE FORMALLY TRAINED SCIENTISTS QUALIFIED IN CHEMICAL, BIOLOGICAL, PHYSICAL, OR IMMUNOLOGICAL EXAMINATION METHODS. PHOTOGRAPHS AND REFERENCES ARE INCLUDED IN THE CHAPTER.