Forensic Science and Criminalistics Introduction Forensic Science and Criminalistics

Scientific Method Empirical Evidence: Analysis: Comparison: Evaluation Knowledge gained from direct observation Analysis: Studying an unknown item to determine its characteristics Comparison: Determining how the characteristics compare with the properties of known items. Evaluation Assessing similarities and differences for identification purposes

Fields of specialization: Forensic: Characteristic of, or suitable for, a court of law. Forensic Science: The application of science to the law. Fields of specialization: Toxicology, psychology, anthropology, chemistry, odontology, serology, fingerprints, firearms, impressions and tool marks, trace analysis, questioned documents.

Individualization No two things in nature are exactly the same. Examples: snowflakes, fingerprints, gun barrels, lip impressions, shoeprints, pieces of broken glass. Class Characteristics: Evidence can be associated only with a group and never with a single source Individual Characteristics: Evidence can be associated with a common source with a high degree of probability

The Modern Crime Laboratory Physical Science Unit: Chemistry, physics, and geology are used in the comparison of crime scene evidence (drugs, glass, paint, explosives, soil) Biology Unit: DNA profiling, comparison of hairs and fibers, comparison of wood and plants.

Document Examination Unit Firearms Unit: Examination of firearms, discharged bullets, cartridge cases, shotgun shells, and ammunition of all types. Also includes examination of firearm residues and tool marks. Document Examination Unit Analysis of paper, ink, typewriters, handwriting, depressions, erasures, and burned or charred documents.

Latent Fingerprint Unit: Photography Unit: Examine and Record photographic evidence, including digital imaging, infrared, ultraviolet, and X-ray photography. Toxicology Unit: Examination of body fluids and organs for the presence of drugs and poisons. Latent Fingerprint Unit: Processing and examination of evidence for latent fingerprints.

Voiceprint Analysis Unit: Use of the sound spectrograph to tie a voice (from a telephoned threat or tape-recorded message) to a particular suspect. The instrument transforms a voice into a visual graphic display called a voiceprint. Evidence Collection Unit: Specially trained personnel go to the crime scene to collect and preserve physical evidence for later processing at the crime laboratory.