Last updated: July 2026
You saw a crash happen. Now what?
The law doesn’t require you to give a statement. But what you saw, or what you’re willing to say about it, can matter more than you’d expect. Witness testimony helps explain how a collision happened and who was at fault, for both the injured party and the insurance companies deciding the claim.
If you’re worried about liability for stopping to help, Illinois’ Good Samaritan Act (745 ILCS 49) protects anyone who provides emergency aid in good faith from civil liability, except for willful or wanton misconduct.
Types of Witnesses
First-Party Witnesses
The drivers and passengers directly involved. Their accounts matter, but carry less weight since they have a financial stake in the outcome, or a relationship with one of the drivers.
Third-Party Witnesses
Pedestrians, cyclists, other drivers, nearby shopkeepers, residents. No stake in the outcome, no connection to either driver, which is exactly what makes their account valuable to adjusters and fact-finders.
A third-party witness doesn’t need to have seen the actual impact to be useful. Someone who noticed a driver failed to signal, or who saw one driver look impaired afterward, still adds real information.
Expert Witnesses
Technical specialists retained to analyze specific evidence, not eyewitnesses. Common types:
- Accident reconstruction experts, rebuild the sequence of events from physical evidence.
- Medical experts, connect the crash to a specific injury.
- Mental health experts, speak to emotional or psychological impact.
- Traffic and highway safety experts, assess road conditions or design as a contributing factor.
- Economists, calculate lost income and future earning capacity.
Unlike lay witnesses, an expert can offer an opinion, not just an account of what they observed.
If You Witness a Crash
Safety first. Get out of traffic, park clear of the scene, call 911 if anyone needs medical help.
You’re not obligated to stay or give a statement. If you do, stick to what you actually observed. Don’t guess at fault, don’t answer questions you’re unsure about, and don’t feel pressured to fill silence with speculation.
If you already left the scene, you can still call it in and describe what you remember. It’s not too late to help.
If No Witnesses Are Available
Sometimes it’s just your word against the other driver’s. If that’s your situation, document everything yourself: photos of the vehicles, the road, skid marks, any visible injuries. Check for nearby businesses or residential cameras that might have caught the crash, even partially. A single angle of usable footage often carries more weight than a witness statement.
How This Affects Your Case
Witness accounts feed directly into how fault gets determined, which in turn affects how much of your damages you recover. If more than one party shares blame, Illinois’ comparative negligence rule means your compensation is reduced by your share of fault, not eliminated entirely, as long as you’re 50% or less responsible.
Frequently Asked Questions
Am I legally required to stop and help after witnessing a car accident?
No. There’s no legal obligation to stop, though most people consider it the right thing to do. Illinois’ Good Samaritan Act protects you from civil liability if you do stop and provide aid in good faith.
Can a witness who didn’t see the actual collision still help my case?
Yes. Someone who noticed a driver’s behavior before or after the crash, such as failing to signal or appearing impaired, can still provide relevant information.
What’s the difference between a lay witness and an expert witness?
A lay witness can only describe what they personally observed. An expert witness, like an accident reconstructionist or medical specialist, can offer a professional opinion based on training and analysis of the evidence.
What if there were no witnesses to my accident?
Document the scene yourself with photos, and check for nearby traffic or business cameras that may have captured the crash.
Need Help Proving Fault in Your Case?
The Illinois personal injury law firm of Phillips Law Offices has a recognized reputation as having aggressive, skilled, and determined representatives and advocates for injured individuals and their families. Whether you’re a witness with questions about your obligations, or you need help finding and working with the right expert witnesses for your case, contact us at (312) 346-4262 for a free case evaluation.
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