When a tractor-trailer hits a passenger vehicle, the evidence that proves what really happened starts disappearing almost immediately. Some of it disappears on a schedule the trucking company controls. Some of it disappears because federal law only requires it to be kept for a limited window. And some of it disappears because the company wants it to.
A preservation letter (sometimes called a spoliation letter or evidence-hold letter) is the legal mechanism that stops that clock.
What is a Preservation Letter?
It is a formal written notice sent to the motor carrier, the driver, the truck’s owner (if different), and often the insurance company, demanding that they preserve specific categories of evidence and warning that destruction or alteration will be treated as spoliation. Once a carrier receives one, any “routine” deletion of relevant records becomes an act they have to explain to a judge.
What to Ask for in the Preservation Letter
A good preservation letter is specific. Vague demands (“preserve everything related to the crash”) let defense lawyers later argue they didn’t know exactly what was at stake. A strong letter calls out:
- The truck itself, unrepaired, including the cab interior and any damage
- The Electronic Control Module (ECM) and Event Data Recorder (a.k.a. the “black box”)
- The Electronic Logging Device (ELD) and all hours-of-service records
- Dashcam footage (forward-facing and driver-facing)
- GPS data
- Dispatch records and communications between the driver and dispatch
- The driver’s qualification file, drug and alcohol testing records, and medical certifications
- The driver’s personnel file, including disciplinary history
- Maintenance records, inspection reports, and repair history
- Any post-crash drug and alcohol testing
- Bills of lading, load tickets, and weight tickets
- Onboard cameras and telematics data
- Cell phone records and any in-cab communications devices
Why Timing Matters
Federal regulations don’t require carriers to keep this material forever. Driver records of duty status and supporting documents must be retained for six months under FMCSA rules. Dashcam footage often overwrites itself on rolling cycles of 30 to 90 days, sometimes less. Some telematics systems hold detailed second-by-second data for only days before downsampling it.
If your preservation letter goes out 90 days after the crash, the dashcam may have already been legally disposed of. If you send the letter promptly after the crash, the carrier will have to defend why they failed to preserve the evidence or face the consequences.
Some federal retention periods are longer. For example, Driver Qualification Files (DQF) must be kept for as long as the driver is employed, plus 3 years thereafter (49 CFR § 391.51). Drug and Alcohol Records must be kept for anywhere from 1 to 5 years, depending on the type of record and whether the test was positive or negative (49 CFR § 382.401). Annual Vehicle Inspections must be kept for 14 months (49 CFR § 396.21).
What Happens if They Destroy Evidence Anyway
That’s where spoliation doctrine kicks in. Florida courts can sanction a party for destroying evidence after being put on notice, including by giving the jury an “adverse inference” instruction which tells them they may assume the destroyed evidence was unfavorable to the party who destroyed it. In a case where the difference between a $500,000 verdict and a $15 million verdict comes down to whether the driver was on his phone, an adverse inference can be everything.
Preservation letters are not optional in a serious trucking case. They are the first move. If your lawyer hasn’t sent one within days of being retained, ask why.
Contact Us for a Free Consultation
If you’ve been injured in a truck accident, call today for a free consultation so our truck accident lawyers can help ensure the evidence is preserved in your case.
