How do I show who caused an accident?
Reviewed by Andrew (Andy) R. Gillin
California State Bar #45226 ↗ · Approval recorded November 4, 2026
How we record review approvalYou need proof of what happened and who failed to use care. You also need to show how that failure caused your injury.
In this guide
Here’s an example
A shop’s camera shows a driver turning into a bike lane. The video helps show what each person did.
A made-up example to explain the idea. Your facts may lead to a different answer.How the rule works
Fault and injury are separate parts of the claim. A video may show an unsafe turn. Care records may help show the harm that followed. You usually need proof of both.
Legal references: [1] California Civil Code § 1714 — Responsibility for harm · [2] CACI No. 430 — Causation: substantial factor (2026 edition)
What can change the answer?
One photo or report may not tell the whole story. Some records may not be allowed in court. Review the proof as a whole.
Court decisions behind this answer
A case can help explain a rule. Its facts and limits matter too.
Mitchell v. Gonzales
Supreme Court of California · 1991
54 Cal.3d 1041, pp. 1049–1053
The court favored a substantial-factor instruction for cause in fact over a confusing older instruction.
Proof of a careless act alone is not enough. The claimed harm must still be linked to that act.
Case applicability reviewed as recorded above.
A useful next step
Save photos, witness names, and care records. Ask for video to be kept before it is erased.
If you are unsure which rule applies, a lawyer can review your facts and any deadlines. Learn about GJEL’s injury representation.
The law behind this guide
The references below support the legal discussion. Their application depends on the facts.
- California Civil Code § 1714 — Responsibility for harm ↗Statute · Review recorded above
- CACI No. 430 — Causation: substantial factor (2026 edition) ↗Jury instructions · Review recorded above
- Mitchell v. Gonzales (1991) 54 Cal.3d 1041 ↗Case law · Review recorded above
Updated 2026-11-04. Read our editorial standards.