Crime Scene Photography 1

Crime Scene Investigation - FRSC 3010 - Fall 2025 - Week #2 - Crime Scene Photography

Course Overview

  • Instructor: John Aitkenhead

  • This lecture is an introduction to the topic of crime scene photography focusing on the use of digital single-lens reflex (DSLR) cameras and their applications in forensic investigations.

Key Topics Covered

  • Photography Basics

  • Role of Crime Scene Photographer

  • Photography Techniques

  • Types of Crime Scene Photos (Scene vs Exhibit)

  • Digital File Formats

  • Camera Settings (Exposure, Aperture, Shutter Speed, Depth of Field)

Introduction to Photography

  • Photography is a broad subject, deserving of focused coursework.

  • This lecture serves as an introductory guide, particularly in relation to DSLR cameras and related processes.

Importance of Photography in Daily Life

  • Rise of personal cell phones has increased the prevalence of photos and videos in daily activities.

  • The public has learned photography techniques largely through experimentation.

  • The advancement of technology has improved the quality of images captured by cell phones, making them comparable to traditional cameras.

  • It is lawful to take photos and videos in public spaces.

Role of Crime Scene Photographer

  • No need for professional training, but competence with cameras and accessories is essential.

  • Formal training may be required for legal purposes.

  • Must understand the criteria for admissibility of photographs in court settings.

Camera Technique

  • Proper handling of the DSLR camera is crucial:

    • Right hand holds the camera body at the right side/grip.

    • Left hand supports the lens from underneath.

Pre-Photograph Considerations

  • Assess if the scene is safe to photograph.

  • Determine required personal protective equipment (PPE).

  • Ensure lawful authority to be present at the scene.

  • Identify the type of crime scene (e.g., murder, robbery, drug-related).

Crime Scene Photography Principles

  • Photograph the scene from various directions and angles to:

    • Document layout and position of evidence.

    • Capture spatial relationships among items.

  • Photographs serve two purposes:

    • Record evidence for expert analysis (e.g., bloodstains, fingerprints).

    • Potentially used as evidence in court proceedings.

Types of Crime Scene Photography

  • Overall Photos: Capture the entire scene as found and provide context for evidence location.

  • Scene Photos: General photos taken before processing, showing everything as it was.

  • Exhibit Photos:

    • A Defined set of images focusing on specific evidence.

    • Consists typically of four photos:

    1. Overall photograph

    2. Mid-range photograph

    3. Close-up photograph

    4. Close-up photograph with scale

Case Study Example

  • Testimony from John Aitkenhead related to a case involving a series of photographs taken at a crime scene, detailing evidence collection including clothing and stains.

Technical Aspects of Digital Photography

  • Digital Photography Definition:

    • Captured by light-sensitive microchips called CCD, recording light on millions of pixels.

  • Charge Coupled Device (CCD): Functions as the digital equivalent of film, storing image as electronic signals.

File Formats

  • JPEG (Joint Photographic Experts Group): Fast, lossy format with quality loss on reopen.

  • TIFF (Tagged Image File Format): High quality, lossless compression, suitable for repeated use.

  • RAW: Proprietary format retaining original data at the highest quality, referred to as the digital "negative".

Exposure Settings

  • Exposure denotes the amount of light reaching the camera sensor. Correct exposure balances light to avoid overexposure (too bright) or underexposure (too dark).

  • Key settings affecting exposure:

    1. Aperture - Size of lens opening.

    2. Shutter Speed - Duration the shutter remains open.

    3. ISO - Sensitivity to light,

  • Photos can be adjusted for exposure using software like Photoshop.

Aperture

  • Defined by f/numbers (f-stops), indicates the lens opening size:

    • Larger numbers (e.g., f/32) = less light; smaller numbers (e.g., f/4) = more light.

    • Moving one f-stop doubles/halves the light captured (e.g., f/8 to f/11 halves light).

Shutter Speed

  • The duration the shutter remains open to expose the sensor to light.

  • Typical shutter speeds: fractions of a second (e.g., 1/500, 1/60). Times longer than 1/60 can cause motion blur.

  • Maximum shutter time on a DSLR is typically 30 seconds.

ISO Sensitivity

  • ISO ratings describe sensor sensitivity to light:

    • Common ranges: 100 - 3200.

    • Increase ISO = brighter photos, may introduce graininess.

Depth of Field

  • Distance between the closest and farthest objects in focus.

  • Controlled by aperture selection, affecting how many elements are sharp in the image.

  • Depth of field is also influenced by:

    1. Distance from the subject.

    2. Focal length of the lens (long focal length = shallow depth; short = deep).

Focal Length of Lens

  • Indicates both angle of view and magnification:

    • Longer focal lengths produce a narrower view with more magnification.

    • Shorter focal lengths provide a broader view with less magnification.

Flash Techniques

  • Several methods of utilizing flash:

    • Direct Flash: Mounted above and directly points to the subject.

    • Feathered Flash: Held off-camera, pointed into scene.

    • Fill-in Flash: Used in bright scenarios to alleviate shadows.

    • Bounce Flash: Softens lighting by bouncing off surfaces.

    • Oblique Flash: Emphasizes details in evidence (e.g., footprints).

    • Multiple Flash (on and off camera): Used in low light situations to enhance visibility.

Photographing Evidence

  • Impression Evidence: Requires careful consideration of lighting and focus to capture detail (e.g., footwear, fingerprints).

  • Establish proper scale and orientation for clear reference.

  • Close-up photos of injuries, vehicle details, and scene elements should all be systematic and respectful to victims.

Vehicle Photography

  • Ensure comprehensive images of both exterior and interior.

  • Include detailed shots of all relevant features: license plates, identifiers, and unique characteristics.

Video Usage in Crime Scenes

  • Videos provide an overview of complex scenes without narration, capturing scene structure and context.

Best Practices for Crime Scene Photography

  • Capture numerous images to ensure documentation is comprehensive.

  • The best approach is to work methodically from general to specific, starting from the outer perimeter of a scene and moving inward.

  • Conditions at the scene (weather, lighting) should inform technique and settings.

Final Considerations

  • Adequate exposure critical for detail; ideally with maximum depth of field.

  • Correct photography yields admissible evidence in court:

    • Photos must be relevant, non-prejudicial, and accurately represent the scene.

  • Digital images may be enhanced for clarity but must not be manipulated to misrepresent.

Summary of Actions When Photographing Crime Scenes

  1. Start outside and progress inward, ensuring to cover every detail.

  2. Utilize overall, mid-range, and close-up photographs as a coherent system for documenting evidence.

  3. Clearly label and scale evidence photographs for clarity and comparison.