# Car Accident Evidence: Dashcams, Vehicle Data, and Video Canonical: https://sanjosecacaraccidentlawyer.com/california-law/digital-evidence/ Reviewed by Andrew Ronald Gillin; reviewed 2026-11-05. Crash video and vehicle records can help explain an event, but useful records may not remain available forever. Preserve lawful copies and ask about proper requests. ## Video and vehicle records to preserve after a crash A dashcam, business camera, trip record, or event data recorder may hold different information. Not every vehicle has the same data, and there is no universal overwrite period for all cameras. A lawyer may need to identify the custodian and the records relevant to the crash. Sources: [Cedars-Sinai Medical Center v. Superior Court (1998) 18 Cal.4th 1](https://law.justia.com/cases/california/supreme-court/4th/18/1.html) ## What an event data recorder may show Keep original files where possible and note where they came from. Avoid editing the only copy, logging into another person’s account, or disturbing a vehicle needed for inspection. Record an accurate description of what you know without claiming that a missing video proves fault. Sources: [Cedars-Sinai Medical Center v. Superior Court (1998) 18 Cal.4th 1](https://law.justia.com/cases/california/supreme-court/4th/18/1.html) ## How to request preservation without accessing private accounts For a useful review, keep the following information together. You do not need to enter it on this website. - The actual policy, bill, report, or notice involved. - Dates and facts that could change which rule applies. - The questions you want an attorney to answer before you take a step. Sources: [Cedars-Sinai Medical Center v. Superior Court (1998) 18 Cal.4th 1](https://law.justia.com/cases/california/supreme-court/4th/18/1.html) ## Court decisions about car accident evidence: dashcams, vehicle data, and video ### Cedars-Sinai Medical Center v. Superior Court (1998) 18 Cal.4th 1, pp. 8–13. The court discussed evidence rules and case sanctions as responses to lost evidence in the setting before it. Limits: It did not create a separate tort claim for that first-party evidence loss. Other facts and rules may differ. [Read the opinion](https://law.justia.com/cases/california/supreme-court/4th/18/1.html) ## Related resources - [San Jose Rear-End Collisions: Fault, Evidence, and Legal Help](https://sanjosecacaraccidentlawyer.com/rear-end-collisions/) - [San Jose Self-Driving Car Crashes: Liability and Evidence](https://sanjosecacaraccidentlawyer.com/autonomous-vehicle-crashes/) - [How to Request a San Jose Car Accident Report](https://sanjosecacaraccidentlawyer.com/san-jose-guide/accident-reports/) ## Legal and agency sources - [Vehicle Code §9951 — Vehicle event data](https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=9951.) - [Cedars-Sinai Medical Center v. Superior Court (1998) 18 Cal.4th 1](https://law.justia.com/cases/california/supreme-court/4th/18/1.html) General information, not legal advice. Examples are hypothetical.