CRIM 25103 - Criminal Investigation - John Brooks. Exam 1 Flashcards.

Historical Foundations

• Bow Street Runners: Early law enforcement group in London, established in the 18th century to combat crime.

• Robert Peel & Principles: Founder of the modern police force; principles include crime prevention, public cooperation, and ethical conduct.

• Rogue Gallery: Collection of criminal photographs used for identification and investigation.

Legal Concepts

• Due Process Revolution: Period in the 1960s where U.S. Supreme Court expanded protections for defendants' rights.

• Landmark Case Involving Defendants’ Rights: Example: Miranda v. Arizona, which established Miranda rights.

• Due Process Clause: Constitutional protection ensuring fair legal proceedings (5th & 14th Amendments).

• Arrest vs. Detention: Arrest involves taking a person into custody; detention is a temporary restriction of movement.

• Ingredients of an Arrest: Intent, authority, custody, understanding by the suspect.

• Affidavit: Written sworn statement; writer is called an affiant.

• Probable Cause: Reasonable belief based on facts that a crime has been committed.

• Exigent Circumstances: Situations allowing law enforcement to act without a warrant.

• Plain View Seizures: Evidence in plain sight can be seized without a warrant.

• Stop and Frisk: Terry v. Ohio ruling allowing officers to pat down suspects for weapons.

• Fruits of the Poisonous Tree Doctrine: Illegally obtained evidence is inadmissible in court.

Crime Classifications & Investigations

• Crime: Violation of the law.

  • Felony: Serious crime, punishable by over a year in prison.

  • Misdemeanor: Less serious crime, punishable by fines or less than a year in jail.

• Investigator: Person responsible for collecting evidence and solving crimes.

• 4 Objectives of Investigation: Establish a crime, identify suspects, gather evidence, present findings.

Crime Scene Management

• Crime Scene & Types:

  • Primary: Original location of the crime.

  • Secondary: Related locations where evidence is found.

• Crime Scene Organization: 3 Major Functions: Scene security, evidence collection, documentation.

• Response to Crime Scene: Secure area, document, collect evidence properly.

• Categories of Evidence: Physical, testimonial, documentary.

• Evidence Recovery Log: Records details of collected evidence.

• Typical Crime Scene Problems: Loss of control can lead to contamination or loss of evidence.

• Crime Scene Documentation: Sketches, notes, video recording.

• Crime Scene Search Considerations: Systematic search, avoid contamination, chain of custody.

• Water Evidence Recovery Protocol: Keep submerged until proper preservation steps are taken.

Forensic Evidence & Identification

• Criminalistics: The study and application of science to criminal investigations.

• Forms of Identification:

  • Anthropometry: Body measurements.

  • Fingerprint Analysis: Unique ridge patterns.

  • DNA Profiling: Genetic identification.

• DNA Definition: Deoxyribonucleic acid; genetic material unique to individuals.

• Physical Evidence: Material objects linking suspect to crime.

  • Two Types: Biological (blood, DNA), Physical (weapons, fingerprints).

• Class vs. Unique Characteristics:

  • Class: Shared among a group (shoe size, blood type).

  • Unique: Specific to an individual (fingerprints, DNA).

• Comparison Samples: Used to match evidence with suspects.

• Footwear Evidence: Labor-intensive, requires proper casting.

• Glass Fractures:

  • Radial Fractures: Extend outward from the impact point.

  • Concentric Fractures: Circular cracks around impact.

• Locard’s Exchange Principle: Contact between individuals and objects results in an exchange of material.

Forensic Identification Techniques

• Fingerprint Types:

  • Latent: Invisible until processed.

  • Patent: Visible prints in substances like blood.

  • Plastic: Impressions left in soft materials.

• Fingerprint Patterns:

  • Loop

  • Whorl

  • Arch

• Laser vs. ALS (Alternative Light Source):

  • Laser: Coherent light, used for fingerprint and trace evidence.

  • ALS: Broad-spectrum light for bodily fluids and fibers.

• Light Sources & Blood Detection: Certain wavelengths reveal blood traces.

• AFIS (Automated Fingerprint Identification System): Digital fingerprint database for matching prints.

• Surface Texture & Blood Spatter: Blood behavior changes with different surfaces.

• Firearms Identification: Analyzing bullet striations, firing pin marks, and gunpowder residue.

Additional Crime Scene Procedures

• Other Documentation Methods: Besides photography, crime scenes can be documented using sketches, written reports, and video recordings.

• Major Considerations in Crime Scene Search: Scene security, search patterns, contamination prevention.

• Typical Crime Scene Problems: Loss of evidence, tampering, environmental factors.

• Control Loss at Crime Scene: Leads to compromised evidence, unverified claims, and hindered investigations.