A spoliation letter, also called a preservation letter, is a written request that a trucking company keep evidence from a crash. It usually names specific records — such as electronic driver logs, engine (ECM) data, camera footage, and maintenance files — and asks the company not to discard, overwrite, or repair them away.
This page is general information, not legal advice. Reading it does not form an attorney-client relationship.
What a spoliation (preservation) letter is
After a serious truck wreck in Oklahoma, much of the useful evidence sits with the trucking company, not with you. A spoliation letter is how you, or a lawyer acting for you, put a request to keep that evidence in writing. It is sometimes called a preservation letter or a preservation demand. It is not a lawsuit, and it is not a government form. It is a notice that identifies the crash and the records the company should keep.
The letter can also go to others who may hold evidence, such as the company's insurer, the owner or lessor of the truck or trailer, a freight broker or shipper, or the tow yard holding the vehicles. A company that never receives the letter may not know to keep what it holds.
Why timing matters after a truck wreck
Federal motor-carrier rules set minimum periods for how long a company must keep certain records. Some of those periods are short.
A motor carrier must retain a driver's records of duty status and supporting documents "for a period of not less than 6 months from the date of receipt" (49 CFR 395.8(k)(1)). The carrier must also "retain for 6 months a back-up copy of the ELD records on a device separate from that on which the original data are stored" (49 CFR 395.22(i)(1)). Driver vehicle inspection reports, the certification of repairs, and the certification of the driver's review must be kept "for three months from the date the written report was prepared" (49 CFR 396.11(a)(4)).
Other records have longer minimums. Inspection, repair, and maintenance records must be retained where the vehicle is housed or maintained "for a period of 1 year and for 6 months after the motor vehicle leaves the motor carrier's control" (49 CFR 396.3(c)). Motor carriers "must maintain an accident register for 3 years after the date of each accident" (49 CFR 390.15(b)). A driver qualification file "shall be retained for as long as a driver is employed by that motor carrier and for three years thereafter" (49 CFR 391.51(c)). Drug and alcohol testing records are kept for one, two, or five years, depending on the type of record (49 CFR 382.401(b)(1)–(3)). Education and training records are kept for an indefinite period: while the individual performs the functions which require the training and for two years after ceasing to perform those functions (49 CFR 382.401(b)(4)).
Those figures are minimum retention periods in the federal rules, as published in the eCFR, up to date as of November 9, 2026. They are not a promise that a company will keep a record longer, and they are not the same as a later court decision about a duty to preserve evidence for a lawsuit.
You do not have to wait for the official crash report before a letter goes out. Waiting can mean a short-clock record has already reached the end of its minimum period, or that a truck has been repaired or put back on the road.
Which records the letter typically asks the company to keep
A letter is more useful when it names records specifically, rather than asking the company to "keep everything." Items often named include:
- Engine control module (ECM) or "black box" data
- Electronic logging device (ELD) records, records of duty status, supporting documents, and the six-month backup copy
- Dashcam or other onboard video, and telematics or GPS data
- The driver qualification file
- Drug and alcohol test records, including post-accident testing records
- Inspection, repair, and maintenance records, including driver vehicle inspection reports
- Dispatch records and other communications about the trip
- Bills of lading or similar shipping documents
- The tractor and trailer themselves, with a request that they not be repaired, salvaged, or sold before they can be inspected
For some of those items, the federal rules state a minimum period. "Dispatchers' sheets, registers, and other records pertaining to movement of transportation equipment" are to be kept for three years (49 CFR Part 379, Appendix A, item J.2). Consignors' shipping orders, tickets, and copies of bills of lading have a one-year period (Appendix A, item I.1(a)).
This page does not cite a federal rule that sets a minimum retention period for ECM data or dashcam video. That is one reason a letter often names those items expressly, and often asks that the truck and trailer be held for inspection.
For a longer table of retention periods, see Preserving Evidence After an Oklahoma Truck Crash. For how ELD records differ from engine (ECM) data, see truck accident investigation.
What Oklahoma law says about preserving evidence
A preservation letter is a request in writing. Whether a legal duty to keep evidence already exists, or later arises, depends on the facts of the case. This page does not tell you that sending a letter automatically creates that duty, or that a court will impose any particular remedy if records are later missing.
The Oklahoma Supreme Court has said that "[a] litigant who is on notice that documents and information in its possession are relevant to litigation or potential litigation or are reasonably calculated to lead to the discovery of admissible evidence has a duty to preserve such evidence" (Barnett v. Simmons, 2008 OK 100, ¶ 20, decided November 10, 2008). In the same opinion, the Court described spoliation as "the destruction or material alteration of evidence or the failure to preserve property for another's use as evidence in pending or reasonably foreseeable litigation" (Barnett, ¶ 21).
Oklahoma also has a uniform civil jury instruction titled "Inference From Spoliation of Evidence" (OUJI-CIV Instruction No. 3.11A, 2022 Supplement). The notes on that instruction say a trial court must first find that there was a duty to preserve the evidence and that a party failed to preserve it. The Supreme Court has also held that sanctions were not authorized where no duty to preserve existed at the time electronic information was deleted under a routine, good-faith retention policy (American Honda Motor Co. v. Thygesen, 2018 OK 14, decided February 13, 2018).
A judge decides whether any instruction or other remedy applies in a particular case. This page does not predict what a court would do in yours.
When to talk with a lawyer
Talk with a lawyer sooner rather than later if you or a family member was hurt in a crash with a commercial truck in Oklahoma, if a loved one was killed, if the truck may already have been moved, repaired, or returned to service, or if an insurance company is asking for a recorded statement. A lawyer can identify who should receive a preservation letter, what the letter should name, and whether other deadlines apply to your situation.
We can review your situation and, if we represent you, send preservation demands. We handle cases on a contingency fee. If there's no recovery, there's no fee. We front the case costs.
For step-by-step first-week guidance, see what to do after a truck crash.
Common questions
What does a spoliation letter do after a truck wreck?
It tells the trucking company, in writing, to keep specified evidence from the crash. The letter should name records such as ELD logs, engine data, camera footage, and maintenance and inspection files. A vague request is easier to overlook.
How long are truck ELD and log records kept under federal rules?
The required minimum is six months. A motor carrier must retain records of duty status and supporting documents "for a period of not less than 6 months from the date of receipt" (49 CFR 395.8(k)(1)). The carrier must also "retain for 6 months a back-up copy of the ELD records" (49 CFR 395.22(i)(1)).
Do I have to wait for the police report?
No. The federal minimum periods described on this page do not wait for the official crash report. Each period starts from its own date, such as the date a record was received or the date of the accident, as the timing section above explains. A lawyer can help send a preservation letter while you are still gathering other documents.