What is a Demand for Preservation of Evidence?
Preserving Evidence in California Personal Injury and Employment Cases
This guide explains how the preservation process works and what plaintiffs should understand early in their case.
Importance of Preservation of Evidence
In many California many cases, especially those involving personal injury (car accidents, slip and falls, dog bites, construction accidents, and premise liability), landlord-tenant disputes, employment law, product liability, medical malpractice, and wrongful death will often have one side that controls much of the critical evidence. This can include video footage, emails, company records, photographs, or other documents. If that evidence is lost or destroyed before trial, it may never be available to prove or disprove a party’s claim.
Once this evidence is gone, it cannot be recovered, and the ability to prove fault, liability, or damages can be significantly impaired. In some cases, the destruction of evidence may be accidental. In others, it may be strategic—especially if the evidence is believed to be harmful to the defendant’s position.
Courts recognize this risk. That’s why California law permits plaintiffs to send a formal notice, called a preservation of evidence letter, to request that individuals and companies retain all relevant materials. If the letter is ignored and key evidence disappears, the judge may issue sanctions, limit testimony, or allow jurors to draw negative inferences about the missing evidence.
This legal framework helps level the playing field, especially in cases where the plaintiff never had control over the information in the first place. It ensures that critical materials aren’t quietly discarded before a formal lawsuit begins or before discovery rules take effect. From a legal strategy standpoint, a well-drafted preservation letter can also bolster a plaintiff’s position in pre-litigation negotiations. It shows that the plaintiff is preparing carefully and treating the matter seriously. More importantly, if the case proceeds to trial and key evidence has been lost despite the warning, the preservation letter can be used to support a motion for sanctions or to argue that the remaining evidence should be “viewed with distrust,” as allowed under California Evidence Code §412.
California Evidence Code §412
If weaker and less satisfactory evidence is offered when it was within the power of the party to produce stronger and more satisfactory evidence, the evidence offered should be viewed with distrust.
What Is a Preservation of Evidence Letter?
A preservation of evidence letter, sometimes referred to as a “litigation hold letter,” is a formal written notice sent by a plaintiff or their legal representative to individuals, businesses, or organizations believed to be in possession of evidence relevant to a potential or ongoing civil case.
The purpose of the letter is twofold: First, it puts the recipient on notice that legal action is being considered or is already underway. Second, it creates a documented request that evidence relevant to the matter—whether physical, digital, or testimonial—be preserved in its current state and not altered, deleted, or discarded. This is particularly important in California, where parties have a duty to preserve evidence once litigation is reasonably foreseeable. The failure to do so can lead to court-imposed sanctions or adverse inferences drawn during trial.
A typical preservation letter includes a summary of the incident in question—such as a car accident, a workplace injury, a discrimination complaint, or a hazardous condition on property. It provides context so the recipient understands what facts are at issue. The letter also specifies the types of evidence that should be preserved. This can include, but is not limited to, surveillance video, photographs, repair logs, inspection records, personnel files, employment correspondence, text messages, internal emails, digital communications, vehicle data, or any relevant documentation. In the case of electronically stored information (ESI), the letter may go a step further and instruct the recipient not to run software updates or dispose of devices that contain metadata or audit trails that might be needed later.
Sample Litigation Hold Letter
Does the other party have to respond to my Preservation of Evidence Letter?
Preservation letters do not require any immediate response from the recipient, and they are not requests for the evidence to be handed over at that time. Rather, they serve as a protective measure to ensure that the evidence remains intact until the formal discovery phase of litigation begins, at which point each party can request relevant materials through subpoenas or discovery motions. Because of this, it’s often in a plaintiff’s best interest to send a preservation letter as soon as possible, especially when there’s a reasonable concern that the evidence may be routinely deleted or altered under the recipient’s internal policies.
Why Evidence Disappears
When an incident happens, there’s often a limited window of time before evidence is erased or discarded:
Surveillance footage may automatically overwrite after a few days.
Emails or text messages can be deleted.
Accident vehicles may be repaired or salvaged.
Witnesses may forget details or become unavailable.
If the defendant or another party controls this evidence, and there’s no legal obligation to preserve it, it may be lost forever—either unintentionally or strategically.
For example, if you were injured in a fall at a gas station due to a spill, the company may discard security footage within a week unless legally instructed to keep it. A preservation letter puts them on notice.
How Courts View Missing Evidence
As we briefly touched above, California law allows courts to view missing evidence with suspicion. Evidence Code §412 provides:
“If weaker and less satisfactory evidence is offered when it was within the power of the party to produce stronger and more satisfactory evidence, the evidence offered should be viewed with distrust.”
This principle is known as the “shall be viewed with distrust” doctrine, and it gives judges and juries the ability to draw adverse inferences against a party who fails to preserve or produce stronger evidence.
For example, if a defendant was expected to provide surveillance footage that could clearly show what happened but instead offers only a written statement from an employee, the court may view that substitution with skepticism, especially if the footage was never preserved. Judges are often asked to evaluate not just whether evidence was lost, but why. The analysis may involve reviewing whether the loss was due to negligence, a failure to implement proper evidence retention protocols, or a willful decision to discard material that could harm a party’s case. Courts consider whether the party had reason to anticipate litigation and whether the preservation duty had already attached at the time the evidence was lost.
While not every missing file or deleted email leads to penalties, the failure to preserve material evidence can significantly affect how a case is litigated and resolved. In situations where the lost evidence was central to proving liability or damages, the court may shift the burden or allow the jury to draw conclusions that favor the opposing party. Understanding this rule is essential for both plaintiffs and defendants. For plaintiffs, it emphasizes the importance of sending preservation letters early and clearly. For defendants or third parties in possession of potential evidence, it serves as a strong reminder that ignoring preservation obligations carries legal risk.
Preserving Electronically Stored Information (ESI)
In today’s legal landscape, electronically stored information (ESI) plays a central role in litigation. Unlike decades past, when most evidence came in the form of physical documents or in-person testimony, a growing portion of modern disputes hinges on digital records, many of which are easy to alter, delete, or lose if not preserved properly from the outset.
Under California law and consistent with federal standards parties have a legal obligation to preserve relevant ESI once litigation is reasonably foreseeable. This duty arises even before a formal complaint is filed. If a party knows, or should reasonably anticipate, that a legal dispute is likely, they are expected to take proactive steps to avoid overwriting, deleting, or otherwise losing relevant digital evidence.
Failure to preserve relevant ESI especially after a preservation obligation has been triggered can result in a legal violation known as spoliation. Courts take spoliation seriously, particularly when the loss of data may unfairly prejudice the opposing party or hinder a fair resolution of the case. If the court determines that ESI was intentionally deleted or negligently lost, it has the authority to impose sanctions. These can include:
ESI Common examples include:
Emails and text messages
Internal chat logs (e.g., Slack, Microsoft Teams)
Spreadsheets, PDFs, and Word documents
Audio and video files, including surveillance footage and call recordings
Phone records and call logs
Server logs and access records
Social media posts, messages, comments, and metadata
Digital photographs and timestamped images
GPS coordinates and location tracking data
Vehicle telematics or “black box” data
These digital records can be essential for proving how events unfolded, who said what and when, or whether a party acted in good faith. In employment cases, for example, emails and internal messages may reveal discriminatory intent or a retaliatory motive. In personal injury or auto accident claims, GPS data and dashcam video may confirm timelines or disprove conflicting accounts.
Metadata and Digital Fingerprints
In the context of civil litigation, metadata often described as “data about data” can be just as important as the primary evidence itself. While a document, image, or email may be the centerpiece of a legal claim or defense, metadata provides critical insight into the context surrounding that piece of information. This can include when it was created, who accessed it, whether it has been altered, and even what device or software was used.
Metadata is particularly valuable in cases where authenticity, timing, or chain of custody is in dispute. For example, in an employment retaliation case, an employer might present a performance review as evidence that a termination was justified. Metadata could reveal that the document was created or altered after the employee filed a complaint casting doubt on its legitimacy and potentially supporting the plaintiff’s claim of retaliation.
In a personal injury case, metadata attached to photographs can show when and where they were taken helping to establish timelines or confirm the condition of a vehicle, property, or injury at a specific moment. Similarly, in contract or business litigation, metadata can establish whether a party backdated a document or made last-minute changes without disclosing them. Because metadata is embedded in the file structure and often not visible through ordinary means (like opening a document), it’s easy to overlook but incredibly difficult to dispute once discovered. It serves as a digital fingerprint, offering an objective record that can either support or undermine a party’s version of events.
Altering or deleting metadata intentionally or not can raise red flags during litigation. Courts may question why metadata is missing, and in some cases, this can lead to spoliation claims or sanctions. For instance, if a party converts Word documents to PDFs before production in a way that strips out creation dates or authorship information, the opposing side may argue that this was done to obscure evidence.
In some instances, even opening and saving a document can overwrite or change its metadata. That’s why parties receiving a preservation of evidence letter are often advised to avoid modifying or opening digital files until they can be safely copied, backed up, or examined by forensic experts.
Courts increasingly expect parties to understand and properly handle metadata. California courts, like those in federal jurisdiction, are empowered to address improper handling of ESI and metadata through discovery orders, adverse inferences, and, in egregious cases, dismissal or default judgment.
Common types of metadata include:
Timestamps – The date and time a file was created, last modified, or last accessed.
Authorship information – The identity of the original creator or user associated with the file.
Edit history – The number of times a file has been opened or edited, and in some systems, a detailed track record of those changes.
Device and software data – Information identifying the hardware or programs used to generate or modify the document.
Geolocation data – GPS coordinates or location tags, particularly common in photos, mobile devices, or vehicle data logs.
Email transmission data – IP addresses, time stamps, sender and recipient metadata, and email client used.
Preservation Best Practices for Metadata
To properly preserve metadata, parties should take steps such as:
Avoiding edits to original files unless done under supervision or with backup copies retained.
Backing up digital files in their native formats, including emails, documents, images, and videos.
Using forensic imaging tools to capture a complete and verifiable copy of the data, including metadata and system files.
Disabling automatic syncing or auto-save functions that could inadvertently alter files.
Consulting with IT professionals or digital forensics experts when the authenticity of digital records may be disputed.
How to Send a Preservation Letter
When litigation is reasonably anticipated such as after a serious accident, a workplace incident, or notice of a potential legal dispute sending a preservation of evidence letter early is a critical step. This letter puts the other party (or parties) on notice that certain documents, recordings, or digital information must be preserved. Once sent, the legal obligation to maintain that evidence begins, and failure to do so can lead to sanctions or adverse inferences in court.
Preservation letters should be directed to anyone who may have control over relevant evidence. This includes not just the opposing party, but potentially third parties such as employers, landlords, contractors, property managers, or even public agencies. The letter should include a brief description of the incident, identify the categories of evidence that should be preserved such as video footage, emails, text messages, internal reports, or medical records and clearly instruct the recipient not to delete, alter, or discard any of it.
To ensure delivery and create a record, it’s best to send the letter via certified mail or a trackable courier service. Email may also be used, especially when communicating with businesses or legal counsel, but it’s advisable to follow up with a hard copy. Keeping a record of delivery and receipt can be important later if there’s a question about whether the duty to preserve was triggered.
While the letter itself is not a court order, courts treat these notices seriously. If relevant evidence is lost after a preservation letter has been sent, judges may impose penalties, limit defenses, or instruct juries to assume the missing evidence would have been unfavorable to the party who failed to preserve it.
Even individuals without legal representation can send a preservation letter, though it’s wise to consult an attorney to ensure it’s clear, specific, and legally sound. A vague or overly broad letter may be ignored or dismissed, whereas a properly written notice makes it harder for the recipient to claim they weren’t aware of their obligations.
Importance of retaining legal counsel
Preserving evidence early in a civil case can protect your legal rights and improve your chances of a fair outcome. Whether you’re dealing with a personal injury, employment dispute, or property damage claim, ensuring that relevant documents, videos, and communications are not lost is often critical.
If you have questions about how to send a preservation of evidence letter, or whether one is appropriate in your situation, Farzan Law can assist.