Lecture 19 tire print evidenc e
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Lecture 19 Tire Print Evidenc e. Evidence Often Overlooked. Vehicle-Involved Scenes. Vehicle-involved scenes run the gamut of scene types: homicides, sexual assaults, burglaries, drive-by shootings, terrorist events, etc.

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Lecture 19 tire print evidenc e

Lecture 19Tire Print Evidence

Evidence Often Overlooked

Lecture 19 tire print evidenc e

Vehicle-Involved Scenes

  • Vehicle-involved scenes run the gamut of scene types: homicides, sexual assaults, burglaries, drive-by shootings, terrorist events, etc.

    • Identifying vehicle should be a critical aspect of any on-scene investigation.

  • In typical homicide investigation, investigators must consider the possibility that specific categories of physical evidence related to the crime are present.

    • Hit and run crimes, whether vehicle-vehicle, vehicle-person, vehicle-other object, involve vehicles that leave the scene.

      • In these crimes, damage creates physical evidence

      • Evidence could prove the culprit vehicle was at the scene;

        • This evidence should be collectable.

Lecture 19 tire print evidenc e

The following article from the New York Daily News is such an example[1]. In this case, the suspect and his vehicle were found. The NYPD crime scene unit had the responsibility of working the car to prove it was the vehicle that struck the victim.

Lecture 19 tire print evidenc e

Case Example an example


  • Hypothetical - Kidnapping

    • Involves a vehicle for transport

    • Critical to find physical evidence that the child had been inside the car,

    • Reality: Such evidence may not be present or had been removed.

  • The abducted child case.

    • No evidence found inside the suspect vehicle proving the child there …

    • Must consider other, indirect, avenues to move investigation forward.

  • The abductor vehicle had been at the scene.

    • Success includes thorough investigation of the outside where the vehicle might have been parked

    • Physical evidence collected and scene archived.

      • One example of physical evidence vehicles leave behind is tire track impressions.

Lecture 19 tire print evidenc e

  • Tire Track Impression Evidence an example

  • Evidence Often Overlooked

  • Footwear Impression:

    • Dealt with locating, enhancing, photographing, etc, footwear impression evidence,

    • Much of that discussion is applicable to tire track evidence as well.

  • Similarities with Footwear Impressions

  • Tire track evidence:

    • Classified as two-dimension (2D) or three-dimension (3D).

  • Commonly in dust or are otherwise contaminated 2D impressions or impressions in a soft surface.

  • Considered Class or individualizing:

    • Physical characteristics needed for meaningful criminalistic-quality comparisons

    • Former provides information about the tread design

    • Latter provides information imbedded into the tread of the tire from daily usage.

Lecture 19 tire print evidenc e

Footwear & Tire Track Differences an example

Their Intrinsic Forensic Values

  • Provides evidence of the individual (shoe impressions) or the vehicle (tire impressions) being at the scene,

    • For tire tracks, suggests the individual vehicle was used in the crime.

  • Tire track impressions geared to identify vehicle … not the person,

    • Although the person might have been driving the vehicle.

Lecture 19 tire print evidenc e

  • How Important is Scene Evidence? an example

  • Identifying specific vehicle requires recovering it and making direct comparisons with physical evidence from scene

  • Scene data allows investigators and laboratory analysts to narrow the search among universe of vehicles.

    • Until suspect vehicle is located and impounded, all scene data must be archived, collected and preserved.

  • Determining which tire tracks to photograph, enhance and or cast is critical

Critical vehicle information crime scene procedures
Critical Vehicle Information an exampleCrime Scene Procedures

Direction of travel

Relationship of impressions @ scene to arrangement of tires on suspect vehicle

Position of front of vehicle

Which impressions made by front & rear tires

Which impressions to photo/cast

Locations where vehicle track measurements will be recorded

Other relevant evidence

Footwear impressions

Fluid spills

  • How vehicle was maneuvered?

  • Vehicle characteristics

    • Stance

    • Track measurements

    • Wheelbase

    • Tread wear indicators

      • Wear bars

  • No. vehicles & no. occupants

  • Were objects loaded or unloaded?

Lecture 19 tire print evidenc e

Success At the Scene an example

One Shot at It

  • Unknown:

    • Whether something seemingly unimportant and ignored will be important as evidence AND suddenly plays a prominent role in the investigation.

  • Consider everything at vehicle-involved scenes as potentially probative.

    • Misperception that tire track impressions have little forensic or investigative value.

  • General scene investigative principles apply equally to vehicle-involved scenes;

    • Management, archiving, searching, etc, are an integral aspect of the investigation.

Crime scene procedures
Crime Scene Procedures an example

Secure the area

Tire prints protected

Obtain information

Case information

Vehicle information

Scene information

Establish safe path to view evidence


Collect/package/preserve evidence

Management an example

  • Should employ guidelines previously discussed

  • While these principles are inviolate

    • Unique characteristics for vehicle-involved scenes.

      • Specifically, identifying, archiving, characterizing and preserving the physical evidence associated with identifying a suspect vehicle.

  • Investigative Questions

  • Archiving

  • Sketching and critical on-scene measurements

  • Vehicle information

  • Suspect information

  • Reconstruction

Archiving an example

Lecture 19 tire print evidenc e

Archiving an example

  • Photographing, sketching, video, 3D-Imaging tire-track and other vehicle-involved scene evidence

    • Much like for footwear impression evidence.

  • For tire track impressions – Document at least 24” of impression

    • For comparison purposes

Considering lighting and glare 3 d impression blocking sunlight using ambient light
Considering Lighting and Glare an example3-D ImpressionBlocking Sunlight Using Ambient Light

Photographing 3 d impressions
Photographing 3-D Impressions an example

Photograph before casting

Reproduces class characteristics

Accidental characteristics are often lost

Spray paint may enhance sufficiently

Outdoor lighting may make it necessary to block direct sunlight

Sometimes sunlight may be superior to oblique lighting

Use polarizing filters to eliminate glare

Look for sidewall information in impression

Lecture 19 tire print evidenc e

Photography – Effect of Lighting an example

  • Existing light blocked out and oblique light provided with off camera Flash

Lecture 19 tire print evidenc e

Archiving 3D Impressions an example



Lecture 19 tire print evidenc e

Archiving 3D Impressions an example


Tire impressions in the snow reverse sidewall impression
Tire Impressions in the Snow an exampleReverse Sidewall Impression

Marking tire impression evidence vehicles still at the scene
Marking Tire Impression Evidence an exampleVehicles Still at the Scene

Photographer’s name, Date, Time

Use scales in plane of impression

Mark tire position on vehicle & on scene

Use spray fluorescent paint for all wheels

Rt front, etc

Arrow pointing to front of vehicle

Establishes inside & outside edge of impression

Impression number

1st or 6th impression recorded @ the scene

N/S directional

Sketches tire track impressions
Sketches an exampleTire Track Impressions

  • Plan sketches: Overview of impressions

    • In-Depth detail not important

      • Measurements

      • Photography

Lecture 19 tire print evidenc e

Archiving – Sketches an example

Include Vehicle-Critical Measurements

  • Sufficiently detailed to permit a determination of specific vehicle characteristics

    • Dependent on the amount and detail of the tire track impressions present.

  • Appropriate measurements must be made.

    • The measurements are the critical data needed to compare the on-scene tracks with a suspect vehicle.