Lecture 14: Vehicle Searches and Bullet Path Analysis

Vehicles can be

a crime scene unto themselves and can encompass any time of crime

Vehicles: there may be questions as to

who drove last, other passengers present, etc

Vehicles: key in vehicle examinations

methodical processing, photography, and documentation 

Vehicles: always work from the* (know this)

outside to the inside (exterior to interior)

Exterior: Notes

Be consistent in labels (drivers side vs passenger side, right vs left, etc)

Technical data: year, manufacturer, model, VIN, license plate #, color, tire info

Visible exterior damage or dirt 

Windows: up/down/broken

Doors: open/closed/sealed with evidence tape 

Exterior: Basic descriptive terms

Insert pic from slide

Exterior: Photography

Overall exterior from all 4 sides and/or all 4 corners of the car

VIN

License plate(s)

Midrange and close-ups of any visible damage

All 4 tires showing the sidewall information

Exterior: Processing

Considerations for fragile evidence first 

fingerprints / ridge detail 

visible RBS 

shoe impressions 

possible bullet holes or defects (label each hole/defect; labeling order does not indicate order of shots)

presumptive testing 

prior to collection, photograph with labels and scales (mid-range and close-up)

Exterior: Measuring

Different ways to accomplish this (stay consistent and be specific in your notes)

Squaring the car: measure 1 inch from each tire and affix a paper or ruler parallel to the vehicle; at a right angle, attached paper or ruler 1 inch from the front/rear of the vehicle

Measuring to specific points on a car: door edge, rocker panel, trim

Exterior: Collection

Collect all evidence from exterior of vehicle to prevent loss or contamination

visible bullets, RBS swabs, fingerprints or shoe prints

Interior: Notes

Include: are the keys in the ignition, odometer and trip readings, headlights on/off, doors locked/unlocked, anything unusual (position of seats and wheel, mirror position, etc), gas level, radio on/off/station set to, temperature controls, interior condition and any damage, does the car start 

Front of drivers seat to brake pedal, headrest to brake pedal, height of seat 

Passenger’s seat to glove compartment lock, headrest to gc lock, height of seat

Interior: Photography

Photograph entire vehicle before moving anything 

Photograph in quadrants and overlapping 

Typical quadrants: driver front, passenger front, driver rear, passenger rear, trunk, center console 

Don’t forget the inside of doors 

Interior: Measuring

Seat positions (prior to moving seats around)

Driver’s area: distance from bottom front of seat to brake pedal, distance from headrest to brake pedal, distance from bottom of steering wheel to floorboard

Passenger’s area: distance from bottom front of seat to glove compartment latch, distance from headrest to glove compartment latch

Interior: Searching

Search methodically by quadrants

For each quadrant: pull everything out and lay on labeled butcher paper, photograph all contents in a quadrant or area of the quadrant, itemize all contents in notes

Don’t forget to look in: glove compartment, pockets of doors, visors, under seats, pockets behind seats, under spare tire

Interior: Processing

Considerations for fragile evidence first 

search for fingerprints / ridge detail 

visible RBS 

touch DNA swabs 

possible bullet holes or defects: label each hole/defect; labeling should be done based on bullet path; presumptive testing 

Prior to collection, photograph with labels and scales (mid-range and close-up)

Photograph with trajectory rods in place from various points of view

Bullet Path Analysis (trajectory): tools

Protractor

Plumb line

Digital inclinometer

Inclinometer with bubble level

Mitering gauge

Bullet Path Analysis (trajectory): Trajectory Rods

Fiberglass, steel, or aluminum brightly colored rods 

Come in different diameters 

2 holes or a hole and impact mark are necessary for angle measurements 

Rods are placed through all holes related to a single shot 

Great tool for visualization and measuring of angles 

Can use cones to stabilize in the holes 

Lasers can be attached to the end to visualize an extended path 

Sagging will occur if too many unsupported rods are pieced together 

Bullet Path Analysis (trajectory): Types of Bullet Impacts

Penetration: bullet enters an object, but does not exit

Perforation: bullet enters and exits an object

Deflection: a direction change after passing through an object

Ricochet: a direction change without passing through an object

Bullet Path Analysis (trajectory): Angles (two types)

Azimuth angle

Vertical angle

Bullet Path Analysis (trajectory): Azimuth Angle

The horizontal angle measured with a bird’s-eye view 

Using a protractor, the protractor must be held level (parallel to the ground)

A plumb bob can be used to help read the angle 

A photo taken directly above can help document the angle 

An orthogonal shot (straight shot) would be considered 90 degrees 

Typically reported as left to right, straight, or right to left 

Bullet Path Analysis (trajectory): Vertical Angle

The ascending or descending angle as a bullet penetrates the surface

Can be measured with a protractor (easiest with an angle finder)

Typically reported as downward, straight, upward