Evidence Preservation Guide

The clock that nobody tells you about

Most people assume the evidence from their crash will still be there when they need it. Much of it will not be.

Commercial vehicle systems, business CCTV and consumer dashcams all overwrite on fixed cycles. Nobody is deleting anything to spite you — the storage simply loops. But the practical effect is the same: the footage that shows what happened can be gone before anyone thinks to ask for it.

What disappears first

• Consumer dashcams — typically loop within hours to days depending on card size.
• Business and traffic CCTV — retention varies widely by operator; some systems keep days, not weeks.
• Commercial truck ECM / event data — may be overwritten in normal operation once the vehicle returns to service.
• Physical scene evidence — skid marks, debris and fluid trails are weather-dependent and often gone within days.

Retention periods are set by whoever owns the equipment, so exact windows vary. That is precisely why a written preservation request sent early matters more than an accurate guess about any one system.

What you can do without a lawyer

Photograph everything you can safely reach, including the other vehicle, its company markings and any visible damage. Note the time of day and conditions. Write down what you remember while it is fresh — memory degrades faster than most people expect.

If a business may have camera coverage of the location, asking early costs nothing. Whether a formal preservation letter is appropriate in your situation is a question for an attorney, and we can connect you with one at no cost.