Crime Scene Investigation Procedures (Lesson 1.04)

Introduction to Crime Scene Investigation

  • The representation of crime scene investigations in television often exaggerates the number of forensic scientists involved.

  • This lesson will address the actual procedures at a crime scene and answer the following questions:

    • What is supposed to happen at a crime scene?

    • Who conducts the investigation?

    • What actions do these investigators take?

    • What are the consequences of effective versus ineffective crime scene investigations?

Goals for the Lesson

  • Identify roles and responsibilities of professionals in the criminal justice system, including:

    • Crime Scene Investigators

    • Criminalists

    • Attorneys

    • Medical Examiners

  • Explain steps of crime scene processing.

  • Develop models to analyze and/or describe information obtained from crime scenes.

  • List and explain sequential steps from the arrival of the first officer to collecting and packaging evidence.

  • Describe the role of each person at a crime scene, including their tools.

  • Explain the concept of chain of custody, including procedures for submitting evidence to a crime laboratory.

  • Define relevant terms:

    • Crime scene

    • Search warrant

    • Constraints from Mincey v. Arizona and Michigan v. Tyler.

Case Example: The Ramsey Case

  • Incident Background: JonBenet Ramsey was reported missing on Christmas Day 1996 in Boulder, Colorado, with her parents receiving a ransom note.

What is a Crime Scene?

  • Definition: A crime scene is determined by the investigator and may change during the investigation.

  • Classification of Crime Scenes includes:

    • Crime scene location: Outdoor, indoor, multiple locations.

    • Type of crime: Robbery, homicide, kidnapping, etc.

    • Scale and environment: Considerations include the physical layout and context of the crime.

Types of Crime Scenes

  • Primary Crime Scene: The original location of the crime (e.g., where a murder is committed).

  • Secondary Crime Scene: Related locations (e.g., where a body is moved).

    • Example: Murder in an alley with a body dumped in a bay.

Types of Crime Scenes Continued

  • The specifics of the crime dictate:

    • Investigators involved.

    • Procedures to follow.

    • Types of evidence collected.

  • Macroscopic vs. Microscopic Crime Scenes:

    • Macroscopic Crime Scene: Includes broader areas like buildings or neighborhoods.

    • Microscopic Crime Scene: Focuses on smaller areas like the immediate vicinity of the body.

Role of First Responders

  • First Responders: Typically police officers with the following responsibilities:

    • Render medical assistance.

    • Secure the crime scene.

    • Preserve evidence and call in criminal investigators.

    • Identify and question witnesses.

Crime Scene Personnel

  • The personnel present may include:

    • Police officers: First responders and evidence protectors.

    • Detectives: Interview witnesses and oversee investigations.

    • Paramedics: Provide medical help.

    • District Attorneys: Determine necessity of search warrants.

    • Medical Examiners/Coroners: Examine deceased for cause and time of death.

    • Crime Scene Investigators: Document the scene and collect evidence.

    • Special Forensic Scientists: Engaged based on the specific evidence (e.g., forensic entomologists).

Process of Securing Evidence

  • Initial Actions by responding officers include:

    • Rendering aid.

    • Brief investigation to secure the area.

  • Documentation and Evidence Collection

    • Perimeter Determination: The lead investigator decides the crime scene’s area.

    • Documentation Techniques: Use sketches, photos, and notes.

Crime Scene Documentation

  • Sketch Artists: Draw dimensions and overall appearance of scenes.

  • Photographers: Capture images from various angles, including evidence and victims.

Real vs. Staged Crime Scenes

  • Importance of identifying whether a scene is real or staged:

    • Staged Crime Scene: Intentionally misrepresented to conceal the true nature (e.g., making it appear a robbery caused loss).

Evidence Collection Methods

  • Systematic searches include:

    • Parallel Search: Line formation from one side to another.

    • Grid Search: Two parallel searches with changes in direction.

    • Zone Search: Dividing the scene into rectangular areas.

    • Spiral Searches: Outward and inward spirals from a focal point.

Evidence Documentation

  • Collection Process:

    • Note the evidence's location.

    • Photograph and bag evidence properly.

    • Unique identifiers and signatures on bags for accountability.

  • Chain of Custody:

    • Process of maintaining the evidence's integrity.

    • All handlers must sign and document their involvement.

Legal Context for Evidence Collection

  • The Fourth Amendment protects citizens' rights against unlawful search and seizure.

  • Search Warrants: Must be obtained based on probable cause and detailed in affidavits.

Important Legal Precedents

  • Mincey v. Arizona:

    • Multiday search without a warrant deemed unlawful.

  • Michigan v. Tyler:

    • Initial fire scene search legal, but subsequent searches without a warrant were illegal.

Investigation Errors in the Ramsey Case

  • Officers sealed JonBenet’s bedroom but failed to search the basement.

  • Evidence gathering from the house was compromised due to unauthorized access by family and friends.

  • John Ramsey discovered the body due to improper handling of the crime scene.

Implications of the Errors

  • The crime scene was heavily compromised, resulting in no admissible evidence available for potential trials.

  • The ongoing unsolved status of the case as of 2012 highlights the importance of correct procedures in investigations.