The strongest evidence in a Los Angeles collision case usually exists for a short window and then is gone. Surveillance systems overwrite. Vehicles get repaired or sold to salvage. Roadway conditions change. Witnesses move.
Almost every difficult liability fight I see traces back to something that could have been captured in the first two weeks. This guide covers what disappears, how quickly, and what can be done about it.
Video: the shortest clock
Along corridors like Wilshire Boulevard, most storefronts, residential buildings, parking structures, and gas stations run cameras that continuously overwrite. Retention of seven to thirty days is typical, and some systems keep far less.
- Identify candidate cameras within a block of the scene, in both directions of travel.
- Send a written preservation request naming the date, a time window, and the camera view — a verbal request to a shift employee rarely reaches whoever administers the system.
- Ask for the native file with its metadata rather than a phone recording of a monitor.
- Public agency footage, including from transit vehicles and some intersections, requires its own request path and has its own retention schedule.
Vehicle evidence
Modern vehicles store crash data. Many passenger cars have an event data recorder capturing seconds of pre-impact speed, braking, throttle, and belt status. Commercial trucks may carry engine control module data, electronic logging device records, and increasingly forward-facing camera systems, all discussed on our truck accident page.
- Photograph both vehicles, all sides, plus the interior and the odometer, before repairs.
- Ask your insurer in writing not to release, repair, or salvage the vehicle until the data can be downloaded.
- Preserve damaged physical items — a helmet, a bicycle, a child seat, footwear — unwashed and unrepaired.
- Note the tow yard and claim number; storage lots dispose of vehicles on their own schedule.
The scene itself
Scene conditions are evidence, and they change. Signal timing gets adjusted, vegetation blocking a sign gets trimmed, a pothole gets patched, a spill gets cleaned.
- Photograph from the sight line of each driver, at the same time of day and in similar light.
- Capture skid marks, gouges, fluid trails, and debris fields with a reference object for scale.
- Record roadway conditions: signal phases, sign visibility, lane markings, lighting, and construction.
- For a fall, photograph the hazard, the surrounding floor, footwear, and any warning signage or absence of it — see our premises liability page.
If a public entity may be responsible for a road or sidewalk condition, the timing is unforgiving: Government Code section 911.2 generally requires a written claim within six months of the incident for personal injury, long before the ordinary two-year deadline in Code of Civil Procedure section 335.1. Our deadline checker covers the general rules.
Witnesses and records
- Collect names, phone numbers, and email addresses at the scene. People become unreachable within weeks.
- Request the traffic collision report and read it for errors in the diagram, direction of travel, and statements attributed to you.
- Keep every medical record and bill, and get evaluated promptly. A delay between the incident and the first visit is routinely used to argue the injury came from something else.
- Keep a short dated log of symptoms, missed work, and activities you could not do. Contemporaneous notes carry more weight than later recollection.
- Preserve your phone data. If a defense argues distraction, your own records can answer it — and deleting anything after a claim arises creates its own problem.
Common mistakes
- Posting about the collision or your activities on social media.
- Giving a recorded statement to the other driver's insurer before reviewing the report.
- Repairing or disposing of the vehicle before it is documented and, where relevant, downloaded.
- Assuming someone else has already secured the video.
If a collision happened recently and you are not sure what to secure first, contact my office. Additional plain-language background is on our car accident learn page and our car accident practice page.
Frequently asked questions
How long do businesses keep security camera footage?
It varies widely. Seven to thirty days is common, and some systems retain much less. Because retention is short, a written preservation request naming the date, time window, and camera view should go out as early as possible.
Can I get the other car’s black box data?
Sometimes. Event data recorder information generally requires access to the vehicle and, when it belongs to another party, consent or a court order, so the vehicle needs to be preserved before it is repaired or salvaged.
Should I repair my car before the claim is resolved?
Document the vehicle thoroughly first, including photographs of all sides and the interior. If crash data or vehicle condition may matter, ask in writing that the vehicle not be repaired or salvaged until it is inspected.
Is the deadline different if a city street caused the crash?
Yes. Claims against California public entities generally require a written claim within six months of the incident under Government Code section 911.2, which is far shorter than the ordinary two-year personal injury deadline.
This is general information, not legal advice. Prior results do not guarantee a similar outcome.