1. Crash Scene Investigation
Law Enforcement II

2. Copyright and Terms of Service
Copyright © Texas Education Agency, These materials are copyrighted © and trademarked ™ as the property of the Texas Education Agency (TEA) and may not be reproduced without the express written permission of TEA, except under the following conditions:
1)  Texas public school districts, charter schools, and Education Service Centers may reproduce and use copies of the Materials and Related Materials for the districts’ and schools’ educational use without obtaining permission from TEA.
2)  Residents of the state of Texas may reproduce and use copies of the Materials and Related Materials for individual personal use only, without obtaining written permission of TEA.
3)  Any portion reproduced must be reproduced in its entirety and remain unedited, unaltered and unchanged in any way.
4)  No monetary charge can be made for the reproduced materials or any document containing them; however, a reasonable charge to cover only the cost of reproduction and distribution may be charged.
Private entities or persons located in Texas that are not Texas public school districts, Texas Education Service Centers, or Texas charter schools or any entity, whether public or private, educational or non-educational, located outside the state of Texas MUST obtain written approval from TEA and will be required to enter into a license agreement that may involve the payment of a licensing fee or a royalty.
Contact TEA Copyrights with any questions you may have.

3. Record/Collect Evidence
Fully identify all parties involved (who)
Record as much vehicle information as possible (what)
CYMBALS
Color
Year
Make/Model
Body style
Additional information
License number
State of registration
Owner information
Damage
Damage (crush) rating
Scrape or skid length
Damage to other items (i.e. poles, rails, or street signs)

4. Record/Collect Evidence (continued)
Interview all parties involved to determine what happened (who, what, and how)
Drivers
Passengers
Witnesses
First responders
Medical personnel
Record all injuries
Determine when the crash occurred (when)

5. Analyze Crash Scene Evidence
Five Mutually Exclusive Categories of Injury
Fatal Injury – any injury that results in death within thirty days of the crash
Incapacitating injury – any injury, other than a fatal injury, which prevents the injured person from walking, driving, or normally continuing the activities he or she was capable of performing before the injury occurred
Non-incapacitating injury – any injury, other than a fatal injury or an incapacitating injury, which is evident to observers at the scene of the crash in which the injury occurred
Possible injury – any reported or claimed injury which is not a fatal injury, incapacitating injury, or non-incapacitating evident injury
No injury – a situation in which there is no reason to believe that the person received any bodily harm from the motor vehicle traffic crash in which he or she was involved

6. Analyze Crash Scene Evidence (continued)
The type classification, also called First Harmful Event, for motor vehicle crashes applies to the nature of the crash and the location of the motor vehicle in relation to the roadway at the time of the first injury or damage-producing event
Two classification categories include broad injury and damage-producing events, collision and non-collision, have ten mutually exclusive categories describing the nature of crashes that may occur on or off the roadway

7. Analyze Crash Scene Evidence (continued)
Non-collision involving a motor vehicle in transport
Overturning
Other non-collision
Collision between a motor vehicle in transport and a(n)
Pedestrian
Motor vehicle in transport
Parked motor vehicle
Railway train
Pedalcyclist
Animal
Fixed object
Other object

8. Drawing Diagrams
Preparing an accurate, legible crash scene diagram is one of the most important tasks performed by crash scene investigators
The crash scene diagram is a graphic representation of the crash scene
The crash scene diagram and the narrative crash report are the records that insurance companies, courts, traffic engineers, and others may review

9. Drawing Diagrams (continued)
Create a field sketch of the scene
A rough drawing that “maps” the crash scene as observed by the crash scene investigator on his or her arrival
The purpose of the field sketch is to assist the investigator in recording measurements taken at the scene
The crash scene investigator should retain the field sketch and rough investigation notes in the case file
The investigator draws the field sketch by first recording the outline of the roadways and then drawing all things relevant to the crash in their relative positions

10. Drawing Diagrams (continued)
The field sketch should include the following information which will appear in the final crash scene diagram:
Features of the roadway (i.e., fog lines, centerlines, etc.)
Positions of vehicles, bodies, debris, blood, etc.
Positions of traffic control devices, including advanced warning devices
Environmental factors such as snow, ice, and standing water
Any item or terrain feature that may have been a factor in the crash
Names of streets and addresses, if applicable

11. Drawing Diagrams (continued)
The field sketch should include the following information which will appear in the final crash scene diagram: (continued)
Type of road surface or other surface information when the crash is off the road
Anything that may have obstructed the driver’s vision and contributed to the crash
Types and locations of road lights if the crash occurred at night
Skid marks or other relevant marks (i.e., tire prints in snow or mud) or gouges
Debris related to the crash
Road grade or superelevation
Lane and road widths
Reference points

12. Drawing Diagrams (continued)
Use numbers to identify the vehicles involved in the crash
Use letters to identify the reference points
Orient the sketch so that north is at the top of the page
Write all information on the sketch so that it is parallel with the top and bottom edges of the sketch
This makes the sketch look neater
It also makes reading the information of the sketch easier

13. Mathematical Calculations
Speed = distance / time or s = d / t
Velocity = 1.466(speed) or v = 1.466(s)
Time = (velocity)(acceleration due to gravity)(drag factor) or t = vgf
Distance = (velocity)(time in seconds) or d = vt

14. Final Scale Drawing Plan
Determine the largest axis (north-south or east-west) with which to orient your paper
Choose the scale of the drawing (i.e., 1 inch = 20 feet, 1 inch = 10 feet, etc.)

15. Final Scale Drawing (continued)
Draw the streets first
Most intersections can be drawn from pairs of parallel lines in either a “┼” or “┬” configuration
Reconstruct angled intersections from the measurements taken by extending the curb lines to form a triangle
Add reference point(s) to the drawing

16. Final Scale Drawing (continued)
Draw (continued)
Draw any other relevant item in its correct position
Decide the scale you will use and record it on your diagram
Draw all of the object and geographic locations within one scale foot of actual measurements

17. Final Scale Drawing (continued)
Draw (continued)
Draw any other relevant item in its correct position (continued)
Designate “North” with the appropriate direction symbol at the top of the page, and write the word “Approximate”
Label all reference points with “Rp” followed by a number
Label all spots as “A, B, C,” etc.
Use a traffic template to draw

18. Final Scale Drawing (continued)
500 Blk N. Cooper St.

19. Final Scale Drawing (continued)
Draw (continued)
Draw any other relevant item in its correct position (continued)
Identify all streets and roads by
Name and number
Composition of surface
Grade
Superelevation
Write all numbers and letters on the drawing parallel to the top and the bottom edges of the paper
Indicate the front of the vehicle with a small triangle, with the point (tip) towards the front of the vehicle

20. Resources Texas Department of Transportation (TXDOT)
Motor Vehicle Crash Manual
Instructions to Police for Reporting Crashes
Vehicle Damage Guide for Crash Investigators
Law Enforcement Explorers Traffic Accident Study Guide
Ed Heads Crash Scene Lesson