In this article, I provide a basic primer for investigating any crash, no matter the severity. The one-page format allows you to cut it out or copy it, laminate it and stick it in your patrol car if you're interested. (Click on PDF link at bottom for one page printable copy)
Before I dive in, though, a word of caution: When responding to a crash, get there. The location can often be minutes, if not hours, away. In such a case, the reported severity of the crash can significantly affect your physiological and physical response levels. The distance hasn't changed, the traffic flow hasn't changed, and the weather hasn't changed. But your mindset has drastically changed. And like a pursuit, heart rate and blood pressure rise, tunnel vision develops, and adrenaline flows.
Bottom line:You can't do any good unless you get there. Take the necessary time appropriate for the situation, and get there safely.
Arriving at the scene of a bad crash can send shivers through even the most seasoned patrol officer. By following the basic guidelines outlined on the next page, you can successfully and safely obtain all of the necessary ingredients needed to conduct a basic crash investigation, or preserve and record the evidence needed by officers in your department who are trained to conduct such investigations. In either case, you owe it to the people involved to conduct the most thorough investigation possible.
Note: Any protocol you follow should be done within the parameters of your department's policy and procedures guidelines.
JP Molnaris a former state trooper and has taught EVOC since 1991 for various agencies. He has also raced cars for 24-plus years and has taught at numerous high-performance racing schools.
Crash Investigation Quick Reference Guide – (pdf for download at end of article)
Establish Initial Traffic Control
Establish preliminary traffic control with your patrol vehicle to protect the scene, preserve evidence and alert traffic that something requires their immediate attention. Park your vehicle so it protects what's in front of you. Make sure it's far enough back so that if it gets hit, it won't be propelled into the crash scene. Save the flares and cones until you've determined the emergency level.
Injuries & Other Emergencies
Ascertain the extent of the emergency and injuries as quickly as possible. Relaying these answers to dispatch will get the appropriate help to the scene. In the case of a non-injury crash, communicating this will allow other responding emergency personnel to downgrade their response mode and maximize their safety.
Permanent Traffic Control
Once you've determined the extent of the crash scene, set up a more permanent traffic control pattern. For cones or flares, walk down the edge of the roadway facing traffic until you get to the farthest point away from your car where you want to establish traffic control. Start at the edge of the fog line, sidewalk, etc., and walk backward, facing traffic, while dropping cones/flares every few feet, each one a little farther out into the lanes you want to block. Eventually, you'll reach the back of your unit, and you will have established the desired lane closure.
This method can be safer than other strategies because it allows you to use the shoulder/sidewalk in relative safety, provides the earliest possible warning to motorists and allows early recognition of hazardous drivers.
If situations dictate, close the roadway completely. Coordinate responding units to locations that allows for safe and efficient traffic control. If needed, contact your local roadway department for cones and barricades. In short, make it work.
Locate Drivers & Witnesses
Locate involved drivers and immediately get their paperwork. This will help ensure they won't leave the scene. Next, identify witnesses and get their statements as soon as possible. Make sure they actually saw the crash occur, not just the aftermath. Tell each witness to find you when they're done. Many important witness statements have disappeared on crash scenes because witnesses have given them to unknown individuals.
Once you've dealt with the witnesses, ask the drivers about what happened, and get statements. Avoid overreliance on statements from passengers their testimony isn't objective. Gather all statements and put them somewhere safe.
Photographs Speak 1,000 Words
If fire personnel plan to cut the roof off of a vehicle to extricate someone, get as many photographs of that vehicle as you can before they start their work.
Also photograph all roadway marks, starting from as far back as you can first see them. Photograph from the level and perspective of what the driver might have seen. Don't use zoom or wide-angle settings because they don't provide an accurate frame of reference when judging distances. Photograph roadway evidence by starting with an overall shot of the area around the evidence, and progressively shoot closer. That way, it can be located at a later time relative to its position in the crash scene. Take as many photographs as you need, and then some.
Examine the Vehicles Involved
Examining both vehicles can give you clues to what occurred. The damage to both vehicles should reflect what drivers and witnesses say happened. In cases of angle crashes, check for horizontal striations in paint that can indicate which vehicles were in motion when the crash occurred. Examine body parts closely for signs of paint transfer.
If needed, and if the vehicles involved have not been moved prior to your arrival, use a can of spray paint to locate each vehicle's tires as well as direction of travel. Spray marks on the roadway identifying the vehicles (e.g., V-1, V-2, etc). If both vehicles have been moved prior to your arrival, it can make identifying what happened more difficult, but not impossible.
Voice of the Roadway
The roadway shows you the vehicle(s)' path prior to collision, the roadway surface factors affecting that path, the area where the actual crash occurred and the paths each vehicle took after impact.
Document all of the roadway evidence as best as possible. Draw a field sketch or diagram. Photograph from the beginning of the crash scene to the final position of rest of each vehicle. Then repeat the process in reverse; investigating the path in both directions will lead to new clues.
Mark all relevant roadway marks with spray paint so they can be located at a later date. Avoid spraying on the actual roadway mark. Instead, mark each end with dots, half circles, etc. Establish a labeling system so you know which roadway mark corresponds to each vehicle if possible. Photograph and write down the existing roadway conditions on the day and time of the crash. Record the roadway marks that are most temporary first, and then concentrate on more indelible marks. Remember, it's better to record too much information than not enough.
Opening the Roadway
No matter where your crash occurs, you're in charge. Obtain all evidence before removing vehicles, debris and any fluids. Identify and examine important debris evidence before it's swept away by a well-intentioned tow truck driver or EMS personnel. Don't open the road until you're satisfied your investigation is complete.
What Happened?
Once you're sure you know what happened, issue the appropriate enforcement action (e.g.: citation, arrest, etc.) and complete all necessary crash paperwork as dictated by your agency. In some situations, a conclusion may not come at the time of the crash.
