Crime Scene Investigation Overview

Crime Scene Investigation

• A methodical process that adheres to set guidelines.
• A dynamic and thoughtful process relying on experience and observation.
• Rooted in the scientific method.

Objectives of Crime Scene Investigation

• Recognize and identify forensic evidence.
• Collect and preserve evidence.
• Reconstruct the crime.
• Assist in the formation of a theory about the crime.

The CSI Effect

• An unrealistic expectation about the capabilities of forensics and crime scene investigations.
• A result of inaccurate depictions of evidence in media, including the rules and responsibilities of law enforcement, the nature of evidence, and procedures.

Roots of Criminal Investigation

• Forensic science is a relatively new career field traced back to approximately 1248.
• It has an interdisciplinary nature, with pioneers in related fields influencing its development.
• Early clan life involved 'Kin policing,' where clan members determined punishments for violators.
• Ancient Hebrews assigned law enforcement responsibilities to kings, high priests, and elders.
• Ancient Babylon codified laws into the 'Laws of Hammurabi,' which introduced the idea of juvenile versus adult court systems.

History of Criminal Investigation - Policing

• The 1750s saw Henry Fielding's establishment of the Bow Street Runners in London, England, who acted as "thief takers" and often accepted cases only from those who could afford the fees.
• The Bow Street Runners were the first professional police force and established practices still in use today, such as hiring informants and conducting criminal raids.
• The Metropolitan Police of London was founded in 1829, followed by the establishment of an investigative unit in 1842.
• The French Sûreté, founded by Eugène François Vidocq in 1810, was the first formal use of detectives in modern times. Vidocq's belief that "only criminals can fight crime" led to the use of undercover investigators in prisons.
• North America saw the implementation of formal, uniformed policing, beginning in Toronto in 1834, Montreal in 1838, and Quebec City in 1840.
• Provincial police forces emerged in rural Eastern Canada in 1867, followed by expansion into the North and West, with the North-West Mounted Police established in 1873.

History of Criminal Investigation - Criminology vs Criminalistics

• Criminology focuses on the study of crime within society and the exploration of criminals and their treatment.
• Criminalistics, also known as forensic science, involves the study of evidence to investigate crimes.

History of Criminal Investigation - Philosophies in Criminology

• Atavism: Cesare Lombroso, considered the "father of modern criminology," believed criminals were born to commit crimes due to biological deviance.
• Positivism: Alexandre Lacassagne, known as the "father of forensic science," believed criminality resulted from social causes.

History of Criminal Investigation - Impact of Criminology on Criminalistics

• The work of Wilfrid Derome, who established the first forensic science laboratory in Canada, followed the Locard model.

Development of Forensic Labs in Canada

• The first forensic science laboratory in Canada was established in Toronto (1932), initially named the Laboratory of the Attorney General in Ontario.
• The laboratory was later renamed to the Centre of Forensic Sciences in 1966.
• The Centre of Forensic Sciences has a central laboratory in Toronto and a regional laboratory in Sault Ste. Marie.

The Crime Lab

• Scientists employed in crime labs are typically civilians who analyze evidence and testify in court.
• A full-service laboratory includes various departments, including toxicology, biology, firearms and toolmarks examination, questioned documents, photo analysis, electronics, and chemistry.
• Crime labs operate under established protocols and guidelines to ensure the integrity of scientific analyses.
• Laboratories can become accredited (legally recognized) through organizations such as the American Society of Crime Laboratory Directors, upholding quality assurance and quality control.

Defining Crimes and a Crime Scene

• A crime is an act punishable by law, deemed a public wrong.
• All crimes are different but may display patterns, which for the offender is known as the modus operandi (Mode of Operation).

Crime Scene Investigators in Canada

• Highly trained, sworn police officers called "Identification Officers."
• May work as general duty, uniformed police officers, Scene of Crime Officers (SOCO), or Identification Officers.
• Civilians can assist in crime scene investigation:
  • Civilian: Someone who has not completed formal police training. They work with police but are sworn.
  • Forensic Identification Assistants: Assists Identification Officers in processing evidence (e.g., Crime Scene Support Techs in Toronto).

Sketching the Crime Scene

• Creates a permanent record of the crime scene and evidence, using units of measurement.
• Routine in major crimes, discretionary for other crimes.
• Two types of sketches:
  • Rough sketch: A preliminary sketch often done during the initial walkthrough.
  • Final (finished) sketch: Prepared for presentation in court based on the rough sketch.

Types of Sketches

• Floor Plan: A two-dimensional sketch providing a bird's-eye view of a room or series of rooms.
• Elevation Plan: A two-dimensional sketch used when the vertical plane is of interest.
• Site Plan: A two-dimensional sketch providing a bird's-eye view of outdoor scenes.
• Cross-Sectional Plan: Also known as "exploded view" or "cross-projection" sketch, combining floor plan and elevation.

Measurements

• All sketches contain measurements.
• Measurements may be taken last as they can be intrusive.

Methods of Measurement

• Triangulation: Measuring the distance from two fixed points to the location of evidence, best for outdoor scenes or tricky contexts (requires multiple people).
• Baseline: Measuring the distance of an object from a baseline at a right angle, best for indoor or outdoor scenes (requires multiple people).
• Polar Coordinates: Also referred to as "map and compass." It involves sighting evidence from a fixed point and measuring its distance and direction (best over large distances, requires two people).
• Perspective Grid Method (Photogrammetry): Places an object of known measurements within a photograph, requiring overlapping photos from multiple angles to limit distortion (requires specialized software).

Chain of Custody

• Essential to prove the integrity of evidence submitted to court; otherwise, it may be deemed inadmissible.
• Must detail the collection process, including who collected the evidence, when it was collected, and where it was collected.

Explore the essential principles and objectives of crime scene investigation. This quiz covers methodologies, the impact of media on forensic expectations, and the historical roots of criminal investigation. Test your understanding of these critical aspects of forensic science.