Criminology Chapter 16

Study Notes

Criminal investigation is a broad term that encompasses various specialties to determine how events unfolded during a criminal incident and establish an evidence-based fact pattern to prove guilt or innocence.
The process becomes more complex when the criminal event is discovered after the fact or when the perpetrator is not clearly identifiable.

Objective Information (indirect): factual proof, including tangible objects presented to a court to prove or disprove a fact, e.g., weapons, fingerprints, fibres, hair, bodily fluids, and digital evidence.
Subjective Information (direct): evidence offered by people directly or indirectly involved in the crime, based on their sensory perceptions.

Revolves around expert and highly specialized laboratory examinations conducted by physicists, chemists, pharmacologists, odontologists, and others.
Combines two sub-systems: forensic tactics and forensic techniques.
Forensic tactics involve the systematic study of criminal methods and techniques used to solve crimes.
Forensic techniques involve analytical methods and modern technological aids to examine physical clues.

Physical Units: examine physical evidence, such as drugs, glass, paint, explosives, and soil.
Biology Units: identify and individualize human body fluids, such as blood, semen, sweat, and saliva.
Trichology (Forensic Analysis of Hair): compares hair samples to determine human or animal origin, species, racial/ethnic origin, male or female, and age.
Ballistic Units: examine firearms, discharged bullets, cartridge cases, and shotgun shells.
Disputed Document Units: examine handwriting and typewriting on questioned documents.
Toxicology Units: analyze body fluids and organs to identify substances and poisons.
Latent Fingerprint Units: detect, process, and examine latent fingerprints.

The crime scene is the area where an unlawful act was committed, and direct and indirect evidence can be found.
Crime scenes can be indoors or outdoors, expansive or small, and may include vehicles.
Scenes can be classified as primary, secondary, organized, disorganized, or mixed.
Processing the crime scene involves securing and isolating the scene, recording the scene, conducting a systematic search, collecting and packaging physical evidence, and maintaining continuity of possession.

Securing the crime scene: stop all activities, remove people, and establish a perimeter.
Recording the scene: uses photography, video recording, audio recording, sketching, and notes.
Conducting a systematic search: involves observing and describing the scene, and searching for physical evidence.
Collecting and packaging physical evidence: ensures evidence is handled and preserved to prevent contamination.
Maintaining continuity of possession: accounts for everyone who handles the evidence, from collection to presentation in court.