How to Authenticate Evidence in California: A Legal Guide

Authenticating evidence is a crucial step in ensuring documents, images, recordings, and other materials are admissible in court. Below, we explain the rules, common authentication methods, and best practices for personal injury or wrongful death litigation in San Diego.

Authentication Under Evidence Code §§ 1400-1402

Under Evidence Code § 1400, authentication means presenting evidence sufficient to support a finding that a writing is what the proponent claims it to be. Evidence Code § 1401 generally requires authentication before a writing, or evidence of its contents, may be admitted.

The term “writing” is broad. It includes documents, photographs, video, audio recordings, emails, text messages, digital files, and other recorded communications or representations, regardless of how they are stored. (Evid. Code § 250.)

When authenticity is disputed, the proponent has the burden of producing evidence sufficient to support a finding that the item is authentic. The judge determines whether the proponent has made that threshold showing. If so, the evidence may be admitted, and the jury determines whether it is credible and how much weight it deserves. The court may also admit evidence conditionally, subject to the necessary foundation being supplied later. (Evid. Code § 403.)

Authentication is only the first step. Establishing that an exhibit is genuine does not necessarily establish that its contents are true or overcome separate objections based on hearsay, relevance, privilege, or other rules of admissibility.

Common Authentication Methods

California law permits multiple valid methods to authenticate evidence under Evidence Code §§ 1410-1421. The most common methods include:

1. Witness Testimony: A person with personal knowledge (such as someone who created, handled, or observed the writing) can testify it’s genuine. (Evid. Code § 1413.)
2. Declaration of Authenticity: A custodian of records may provide a written declaration certifying the authenticity of business records, commonly used for medical, billing, employment, or financial documents. This method is often more efficient than live testimony and can support admission under the business records exception to hearsay. (Evid. Code § 1561.)
3. Admissions and Stipulations: If the opposing party admits the document’s authenticity or acts on it as genuine, no further proof is required. (Evid. Code § 1414.)
4. Judicial Notice: Certain types of evidence (e.g., court files and records, statutes, even Google Maps images) may be authenticated by judicial notice. (Evid. Code § 451, § 452.)

Let’s explore each of these methods in greater detail.

Witness Testimony

A writing may be authenticated by anyone who saw the writing made or executed. (Evid. Code § 1413.) More broadly, a writing may also be authenticated by anyone with personal knowledge to lay a basic foundation for the evidence. For example, a witness can be asked the following questions to authenticate evidence:

1. Do you recognize what has been marked for identification as Exhibit “x”?
2. What is it?
3. How do you recognize it?
4. Is it true and accurate?

The witness does not have to have created or observed the creation of the evidence to authenticate it. The Evidence Code does not limit the means of authentication (Evid. Code § 1410), and a subscribing witness is never required (Evid. Code § 1411).

The questions should be tailored to the exhibit. For example, a witness authenticating a photograph may testify that it fairly and accurately depicts a location, while the recipient of an email may identify the sender, explain how the email was received, and confirm that the exhibit accurately reproduces the message.

Custodian of Records Declaration

Business records are commonly authenticated through an affidavit or declaration from the custodian of records or another qualified witness.

Subpoenaed records are required to be produced along with a declaration of authenticity. (Code Civ. Proc. § 2020.430.) A declaration of authenticity is an affidavit signed by the custodian of records certifying the authenticity of the business records. (Evid. Code § 1561.)

Specifically, the affidavit must state the following:

1. The affiant is the duly authorized custodian of the records or other qualified witness and has authority to certify the records.
2. The copy is a true copy of all the records described in the subpoena, or [...] the records were delivered to the attorney, the attorney’s representative, or deposition officer for copying at the custodian’s or witness’ place of business, as the case may be.
3. The records were prepared by the personnel of the business in the ordinary course of business at or near the time of the act, condition, or event.
4. The identity of the records.
5. A description of the mode of preparation of the records.

(Evid. Code § 1561.)

An affidavit that meets these requirements is admissible at trial to establish the authenticity of the records produced. (Evid. Code § 1562.)

Admissions and Stipulations

A writing may be authenticated by evidence that the opposing party admitted its authenticity or treated it as authentic. (Evid. Code § 1414.) For example, a party’s response to an email, performance under a contract, or payment of an invoice may help establish that the party recognized the writing as genuine.

Requests for admission. A party may serve requests for admission asking another party to admit the genuineness of attached documents. Each document should be separately identified and attached as a numbered exhibit. (Code Civ. Proc. § 2033.060(g).)

A request may state: “Admit that the document attached as Exhibit 1 is genuine.”

Judicial Council Form DISC-020 may also be used to request admissions concerning the genuineness of documents. When necessary, serve separate requests addressing the relevant facts or contents. An admission that a document is genuine does not necessarily establish that every statement in it is true or otherwise admissible.

Stipulations. The parties may also enter a written stipulation, or place an agreement on the record, establishing the authenticity of exhibits for trial. A stipulation can save substantial trial time, but its scope should be stated carefully. For example: “Documents produced by a party or nonparty in response to formal discovery or compulsory process shall be deemed authentic for purposes of this action. This stipulation concerns authenticity only and does not waive objections based on hearsay, relevance, privilege, or any other ground.”

Do not rely on an anticipated stipulation as the only authentication plan. If the opposing party refuses to stipulate or narrows the agreement before trial, the proponent must be prepared to establish authenticity through witnesses, declarations, admissions, or other evidence.

Judicial Notice

Judicial notice extends to facts “not reasonably subject to dispute” that are “capable of immediate and accurate determination by resort to sources of reasonably indisputable accuracy.” (Evid. Code § 452(h).) Courts routinely take judicial notice of the records of any California or federal court (Evid. Code § 452(d)), official acts of the legislative, executive, and judicial branches (§ 452(c)), recorded real-property documents such as deeds, and statutes, regulations, and local ordinances.

Google Maps Images. Increasingly, Courts have treated mainstream mapping services (e.g., Google Maps, Google Earth, Bing Maps) as subject to judicial notice.

• California authority: In People v. Bratton (2023) 95 Cal.App.5th 1100, the Court of Appeal granted judicial notice of a current Google Maps view of the area where the crime occurred, under Evidence Code §§ 452(h) and 459(a), after the original map exhibits had been destroyed.
• Federal authority: The Ninth Circuit has taken judicial notice of a Google map and satellite image as a source “whose accuracy cannot reasonably be questioned” (United States v. Perea-Rey (9th Cir. 2012) 680 F.3d 1179, 1182, fn. 1), and other federal circuits have followed suit (Pahls v. Thomas (10th Cir. 2013) 718 F.3d 1210, 1216). Federal district courts now routinely extend the same treatment to Street View images.
• Ask properly: In the trial court, judicial notice of a matter under Evidence Code § 452 becomes mandatory if a party requests it, gives each adverse party sufficient notice, and furnishes the court with sufficient information. (Evid. Code § 453.) We recommend filing requests for judicial notice along with your motions in limine.

Other Authentication Methods

In addition to witness testimony, declarations, admissions, and judicial notice, California law recognizes statutory presumptions and other methods that may establish authenticity.

Self-Authenticating

Certain writings are presumed to be authentic (i.e., self-authenticating). These include:

• Notarized signatures: a certificate of acknowledgment on a deed, mortgage, or other acknowledged writing is prima facie evidence of the genuineness of the signature (Evid. Code § 1451).
• Documents bearing the seal of a public entity (Evid. Code § 1452, Code Civ. Proc. § 1931.)
• Documents bearing an official or corporate signature (Evid. Code § 1453; Corp. Code § 313.)
• Regularly published newspapers (Evid. Code § 645.1.)
• Printed representations of computer information (Evid. Code § 1552, § 1553.)

Handwriting

A writing may be authenticated by evidence of the genuineness of the handwriting of the maker. (Evid. Code § 1415.)

• Lay Witness: A witness who is not otherwise qualified to testify as an expert may state his opinion whether a writing is in the handwriting of a supposed writer if the court finds that he has personal knowledge of the handwriting of the supposed writer. (Evid. Code § 1416.)
• Trier of Fact: The genuineness of handwriting, or the lack thereof, may be proved by a comparison made by the trier of fact. (Evid. Code § 1417.)
• Expert Witness: The genuineness of writing, or the lack thereof, may be proved by a comparison made by an expert witness. (Evid. Code § 1418.)

Contents and Circumstantial Evidence

A writing may be authenticated by evidence that the writing contains matters that are unlikely to be known to anyone other than the claimed author. (Evid. Code § 1421.)

Evidence may also be authenticated by circumstantial evidence. The Evidence Code does not exhaustively list all means of authentication: “Nothing in this article shall be construed to limit the means by which a writing may be authenticated or proved.” (Evid. Code § 1410.)

Courts therefore consider the combined circumstances and ask whether they are sufficient to support a finding that the evidence is what its proponent claims. “Circumstantial evidence, content, and location are all valid means of authentication.” (People v. Gibson (2001) 90 Cal.App.4th 371, 383.) There are “innumerable ways in which a document may be authenticated by circumstantial evidence,” if the evidence is “sufficient to sustain a finding that it is the writing that the proponent of the evidence claims it is.” (McAllister v. George (1977) 73 Cal.App.3d 258, 262-263.)

Practical Examples of Authentication

Emails

Authenticating an email ordinarily involves two questions: whether the exhibit accurately reproduces the stored email and whether the message can be attributed to the claimed sender. Under Evidence Code § 1552, a printed representation of computer information is presumed accurate unless the opposing party introduces evidence that it is inaccurate or unreliable. That presumption concerns only the accuracy of the reproduction. It does not establish who authored or authorized the message.

An email may be authenticated through:

• Testimony from the sender or recipient
• Evidence that the claimed sender owned or regularly used the email address
• A reply responding to an earlier authenticated communication
• A signature block, contact information, or other identifying details
• Contents referring to facts unlikely to be known by anyone other than the claimed author
• Attachments, subsequent conduct, or other corroborating circumstances
• Metadata, native files, email headers, or provider and server records
• An admission obtained through written discovery or deposition testimony

Evidence Code § 1420 addresses writings received in response to an earlier communication. Evidence Code § 1421 permits authentication through information unlikely to be known by anyone other than the claimed author.

For significant email evidence, counsel should preserve the native message, complete headers, attachments, and entire conversation. A forwarded chain may raise separate authentication and hearsay questions about the embedded messages. Production in discovery may support authenticity, but the safer practice is to obtain an admission through a request for admission or establish the foundation during deposition.

Text Messages

Text messages, iMessages, and messages exchanged through applications such as WhatsApp or Signal are writings that must be authenticated before admission. As with emails, the proponent should distinguish between proving that the exhibit accurately depicts the messages displayed on a device and proving that a particular person authored or sent them.

Text messages may be authenticated through:

• Testimony from the sender or recipient
• Evidence connecting the telephone number or account to the claimed sender
• The claimed sender’s possession or regular use of the device
• A continuous exchange in which the messages logically respond to one another
• Nicknames, private facts, writing patterns, or other distinctive contents
• Timestamps, metadata, native exports, or forensic device extractions
• Carrier, application, or account records
• Admissions obtained through written discovery or deposition testimony

A contact name or telephone number displayed in a screenshot may not be sufficient by itself. The foundation should explain how the witness knows that the number or account belongs to the claimed sender and identify circumstances connecting that person to the conversation.

In People v. Calhoun (2019) 38 Cal.App.5th 275, 313-315, the Fourth District, Division Three held that text messages extracted from cell phones were sufficiently authenticated through testimony connecting the phones and numbers to the participants, together with the contents of the messages. The court explained that authenticity may be established through contents and circumstantial evidence without testimony from the author.

More recently, Adoption of X.D. (2025) 114 Cal.App.5th 812 held that screenshots of forwarded text messages were sufficiently authenticated through witness testimony, an admitted telephone number, a distinctive contact name, and message contents corroborated by other evidence. Testimony from the person who originally received and forwarded the screenshots was not required.

Whenever possible, counsel should preserve the complete conversation rather than isolated screenshots. Native messages, surrounding exchanges, device information, and metadata can provide important context and help address claims of alteration, shared-device use, or spoofing.

Authentication does not establish the truth of the messages or resolve hearsay objections. Messages authored by an opposing party may be admissible under Evidence Code § 1220. Statements by other participants require a separate hearsay exception or a relevant nonhearsay purpose.

Photographs and Video

Photographs and video recordings may be authenticated through a percipient witness or evidence establishing the reliability of the recording itself. The person who took the photograph or made the recording need not testify.

Photographs and videos may be authenticated through:

• Testimony from someone who observed the depicted scene or event
• Testimony from the photographer or person who made the recording
• Evidence explaining when, where, and how the image was created
• Testimony from a custodian, employee, or other person familiar with the recording system
• Recognizable people, locations, objects, timestamps, or other circumstantial evidence
• Metadata, native files, file history, or chain-of-custody evidence
• Admissions obtained through written discovery or deposition testimony

Under the traditional pictorial-testimony method, a witness who observed the scene or event may testify that the photograph or video fairly and accurately depicts what the witness saw. The witness need not be the photographer. The image is admitted as a visual representation of the witness’s testimony.

When no percipient witness observed the recorded event, the image may instead be authenticated under the silent-witness method. The proponent must present evidence sufficient to support a finding that the recording is genuine. Depending on the circumstances, the foundation may include how the recording system operated, how the file was retrieved and preserved, timestamps or metadata, recognizable contents, and other evidence connecting the recording to the relevant event.

In People v. Bowley (1963) 59 Cal.2d 855, 859-862, the California Supreme Court recognized that a photograph may be admitted as substantive evidence even when no eyewitness can confirm what it depicts, provided other evidence establishes its accuracy.

In People v. Goldsmith (2014) 59 Cal.4th 258, 267-272, the Court applied that principle to images and data generated by an automated traffic-camera system. The Court held that authentication may rest on witness testimony, circumstantial evidence, the contents of the images, and applicable statutory presumptions. It declined to require expert testimony merely because digital images can theoretically be manipulated.

Evidence Code § 1553 provides that a printed representation of images stored on video or digital media is presumed accurate. If the opposing party introduces evidence that the representation is inaccurate or unreliable, the proponent must prove its accuracy by a preponderance of the evidence.

For edited, enhanced, or excerpted evidence, counsel should preserve the original file and document each change. Cropping, enlargement, stabilization, or brightness adjustment does not necessarily make an image inadmissible, but the proponent should be prepared to establish that the process did not materially alter what the image depicts. Expert testimony is not ordinarily required, although it may become important when there is concrete evidence of manipulation or a genuine dispute about the recording process.

Website Pages

A webpage, printout, or screenshot is a writing that must be authenticated. The fact that material appears online, even on a party’s apparent website, does not establish that the party owned, controlled, or authorized it.

A webpage may be authenticated through:

• Testimony from someone who viewed or captured the page
• The complete URL and the date and time the page was accessed
• Domain-registration or account-ownership records
• Logos, branding, addresses, telephone numbers, and contact information
• Contents connecting the page to the claimed owner or author
• Metadata, source files, or website-host records
• Testimony from a webmaster, employee, or records custodian
• Admissions obtained through written discovery or deposition testimony

A witness who personally viewed the webpage may testify that the exhibit fairly and accurately depicts the page as it appeared on a particular date. Evidence Code § 1552 creates a rebuttable presumption that a printed representation of computer information accurately represents what it purports to show. The presumption helps establish the printout’s accuracy, but not who created, controlled, or authorized the underlying content.

In People v. Valdez (2011) 201 Cal.App.4th 1429, 1434-1436, the Fourth District held that a MySpace page was adequately authenticated through its photographs, written content, personal details, and evidence connecting the password-protected account to the defendant. The proponent did not have to eliminate every possibility of falsification. The evidence needed only to support a reasonable finding that the page was what the proponent claimed.

Archived pages require additional care because the witness may not have viewed the website when the material was originally published. When using the Internet Archive’s Wayback Machine, counsel should preserve the archived URL, capture date, retrieval date, and complete page. The strongest foundation may include an Internet Archive declaration, testimony from someone familiar with the original website, discovery admissions, or records connecting the archived material to the website owner. No published California appellate decision appears to hold that an Internet Archive declaration is invariably required.

Judicial notice ordinarily cannot substitute for authentication or establish the truth of statements published online. A court may notice that a website exists or contains particular material, but generally may not accept disputed assertions on the website as true. See Ragland v. U.S. Bank National Assn. (2012) 209 Cal.App.4th 182, 193, and Jolley v. Chase Home Finance, LLC (2013) 213 Cal.App.4th 872, 889.

Authentication also does not establish that the website’s statements are admissible for their truth. Once the page is connected to a party, an authorized statement may qualify as a party admission under Evidence Code § 1220. Additional evidence may be needed to establish that an employee or third party was authorized to speak for an organization.

Social Media Posts

Authenticating social media evidence may require three related showings: that the exhibit accurately reproduces the online material, that the account belonged to or was controlled by the claimed person, and that the person authored or authorized the particular post or message. Establishing account ownership does not necessarily establish authorship of everything published through it.

Social media evidence may be authenticated through:

• An admission from the account owner or author
• Testimony from someone who viewed, received, or captured the material
• A username, profile photograph, biography, or other personal identifiers
• A linked email address, telephone number, or device
• Evidence that the person regularly used or controlled the account
• Distinctive language, private facts, locations, or references to surrounding events
• Consistent photographs, captions, comments, and account history
• Metadata, platform records, or forensic extraction from a device
• Admissions obtained through written discovery or deposition testimony

In People v. Cruz (2020) 46 Cal.App.5th 715, 729-731, the Fourth District held that Facebook messages sent through fictitious accounts were adequately authenticated by their distinctive contents and corroborating testimony. Once the proponent makes the required prima facie showing, competing explanations generally affect the evidence’s weight rather than its admissibility.

Counsel should preserve the complete post, account name, profile information, URL, date, comments, and surrounding content rather than relying on a cropped screenshot. When possible, discovery admissions or deposition testimony should establish account ownership, authorship, and the exhibit’s accuracy. Platform records may provide additional support, although obtaining content directly from a social media provider can present separate statutory and practical obstacles.

Surveillance and Dash Cam Footage

Surveillance, dash cam, and body camera recordings may be authenticated by a percipient witness who testifies that the recording fairly and accurately depicts what the witness observed. When no percipient witness is available, the recording may be authenticated under the silent-witness method through evidence showing that it reliably recorded the relevant event.

Useful foundational evidence may include:

• Testimony from a witness who observed the recorded event
• The camera’s location, field of view, and recording capabilities
• How the system recorded, stored, and retained footage
• Whether the system was operating properly at the relevant time
• The accuracy of the date and time stamp or an explanation of any discrepancy
• Who retrieved or exported the footage and how
• Whether the exhibit contains the complete recording or an excerpt
• Whether the footage was converted, enhanced, compressed, or otherwise modified
• The native file, metadata, audit logs, or checksum information, when available
• A discovery admission, stipulation, or custodian declaration establishing authenticity

A compliant custodian declaration accompanying subpoenaed business records may establish authenticity under Evidence Code §§ 1561 and 1562, but authentication and the business-records hearsay exception remain separate requirements.

In People v. Goldsmith (2014) 59 Cal.4th 258, 267-272, the California Supreme Court upheld the authentication of automatically generated camera evidence based on testimony about the recording system, the contents of the images, and other circumstantial evidence. The Court emphasized that authentication is flexible and does not invariably require testimony from the technician who installed or maintained the system.

By contrast, a recording cannot be considered merely because its contents appear relevant. In McGarry v. Sax (2008) 158 Cal.App.4th 983, 990, the court declined to consider a videotape and still photographs that had not been authenticated.

Google Maps and Street View

Courts may take judicial notice of basic geographic facts shown by a reliable mapping service when those facts are not reasonably subject to dispute and can be immediately and accurately determined. (Evid. Code § 452(h).) People v. Bratton (2023) 95 Cal.App.5th 1100, discussed above, applied that rule to a current Google Maps view under Evidence Code §§ 452 and 459.

That ruling does not permit judicial notice of every fact displayed by Google Maps or Street View. A current map may establish street locations or the general layout of an area, but ordinarily cannot prove that a particular roadway defect, traffic control, obstruction, or property condition existed on an earlier disputed date. Judicial notice becomes mandatory when a party properly requests it, gives the opposing parties sufficient notice, and provides the court with enough information to take notice (Evid. Code § 453), but § 453 does not expand the categories of facts subject to notice. Use judicial notice for basic, undisputed geography, and lay a conventional evidentiary foundation for disputed historical conditions.

Sargenti v. City of Long Beach (2026) 120 Cal.App.5th 702, 716 shows what happens when that foundation is skipped. The plaintiff relied on a historical Google Street View screenshot to show that an asphalt patch existed approximately five years before his accident. The Court of Appeal held that the screenshot was inadmissible and could not create a triable issue on constructive notice because it had not been authenticated. Counsel’s declaration did not identify who captured the screenshot, when it was captured, how the historical image was located, or how its accuracy was established.

Google Maps, satellite images, and Street View photographs may be authenticated through admissions, witness testimony, circumstantial evidence, or records produced by Google. The required foundation depends on what the exhibit is offered to prove. Useful steps include:

• Preserve the complete image with the displayed address, capture date, orientation, and other identifying information.
• Preserve the image’s complete URL. The URL allows Google to identify the specific image in response to a subpoena.
• Serve a request for admission addressing the exhibit’s genuineness, depicted location, capture date, and relevant physical conditions.
• Seek a stipulation identifying the precise facts established by the image.
• Use a witness familiar with the location to testify that the image fairly and accurately depicts it at the relevant time.
• If the image predates or postdates the incident, establish whether material conditions changed during the intervening period.
• For historical Street View images, subpoena the image from Google and include its URL in the subpoena. Google will produce responsive imagery with a custodian-of-records affidavit, providing a practical way to authenticate the image and its capture date without live testimony from a Google witness.
• Do not rely solely on an attorney declaration to authenticate a historical Street View image.

A subpoena to Google that identifies the precise image by URL and results in production with a custodian affidavit addresses the foundational problem in Sargenti. This method is particularly useful when historical imagery is offered to show that a roadway or property condition existed before an incident.

Medical and Billing Records

Medical and billing records ordinarily must be authenticated and admitted under a hearsay exception. When subpoenaed records are accompanied by a declaration complying with Evidence Code § 1561, the declaration may establish the authenticity and business-record foundation required by Evidence Code § 1271 without live custodian testimony. Evidence Code § 1562 makes the declaration admissible and creates a presumption that its statements are true. (Evid. Code § 1562.)

Before relying on the declaration, confirm that it:

• Identifies the affiant as the authorized custodian or another qualified witness
• Identifies the records and the provider or business that created them
• States that the production is a true copy of all records described in the subpoena
• States that business personnel prepared the records in the ordinary course of business
• States that the records were prepared at or near the time of the recorded act, condition, or event
• Describes the records’ mode of preparation
• States whether any requested records could not be located or do not exist
• Covers each provider, facility, billing entity, and electronic record system represented in the production

Additional practical considerations include:

• Obtain records directly from the provider by subpoena whenever possible. Records supplied by the patient ordinarily lack the foundation required for the business-record exception. Alternatively, request a custodian affidavit with the patient request.
• Review declarations before trial because incomplete affidavits may be insufficient.
• Determine whether the medical and billing records came from different entities or systems. One custodian’s declaration may not establish the foundation for records created by an unrelated provider.
• Distinguish authenticity from the business-record exception. A stipulation that records are genuine does not necessarily establish compliance with § 1271.
• Review the records for hearsay within hearsay. Statements attributed to a patient, family member, bystander, referring provider, or other third party may require an independent exception if offered for their truth.
• Determine whether diagnoses and opinions are offered as entries in the treatment history or as substantive proof of disputed causation, prognosis, or future care.
• Use a treating physician or other qualified expert when testimony is needed to explain the records or establish medical causation, prognosis, the reasonableness and necessity of treatment, or the significance of particular findings.
• For billing records, remember that authenticating the amounts charged does not establish that the charges were reasonable, the treatment was medically necessary, or the billed amounts are recoverable as damages.

In Vargas v. Gallizzi (2023) 96 Cal.App.5th 362, the Court of Appeal confirmed that declarations under §§ 1561 and 1562 may establish the foundational requirements of § 1271. The case also illustrates the difference between admitting that medical records are genuine and admitting them under the business-record exception.

Likewise, Conservatorship of S.A. (2018) 25 Cal.App.5th 438, 447 held that properly authenticated medical records were admissible under the business-record exception to prove the acts, conditions, and events recorded in them. By contrast, People v. McVey (2018) 24 Cal.App.5th 405, 414 upheld the exclusion of medical records where the proponent lacked a custodian declaration, qualified witness, or other adequate business-record foundation.

Physical Evidence

Physical evidence may include an accident vehicle, component part, damaged clothing, tire, roadway material, biological sample, or other tangible object. The proponent must present sufficient evidence for the court to find that the item is what the proponent claims. (Evid. Code § 403(a)(3).)

A distinctive object may be identified by a witness familiar with it. An accident vehicle, for example, may be identified by its vehicle identification number, license plate, photographs, damage pattern, or other distinctive features. A detailed chain of custody becomes more important when an item is fungible, easily contaminated or substituted, or subjected to laboratory or destructive testing.

Useful preservation and foundation steps include:

• Photograph and record the item from all relevant angles before moving, cleaning, repairing, or disassembling it.
• Record serial numbers, vehicle identification numbers, labels, dimensions, markings, and distinctive damage.
• Identify who recovered the item, where and when it was recovered, and how it was connected to the incident.
• Store the item in a secure, weather-protected location.
• Maintain a log of each person who possessed, moved, inspected, or tested the item.
• Preserve packaging, labels, broken pieces, removed components, and material generated during testing.
• Document repairs, disassembly, corrosion, environmental exposure, and other changes in condition.
• Clearly identify replacement or substituted components and keep them separate from the originals.
• Give affected parties reasonable notice and an opportunity to inspect before destructive testing.
• Use an agreed or court-approved protocol when testing could consume or materially alter the evidence.
• Preserve representative samples when possible and document destructive testing through photographs, measurements, notes, and video.
• Prepare the recovering witness, custodian, and testing expert to identify the item and explain its handling and condition.

In People v. Catlin (2001) 26 Cal.4th 81, 134, the California Supreme Court explained that the proponent must show, considering all the circumstances and the ease of alteration, that it is reasonably certain no material alteration occurred. A perfect chain is not required. When the possibility of tampering or substitution rests on speculation, the remaining doubt ordinarily affects weight rather than admissibility.

The duty to preserve evidence arises when litigation is reasonably foreseeable, meaning probable or likely rather than a mere possibility. (Victor Valley Union High School Dist. v. Superior Court (2023) 91 Cal.App.5th 1121.) Depending on the circumstances, unilateral disposal or material alteration may support discovery sanctions, exclusion of testing evidence, or an adverse inference under Evidence Code § 413. Counsel should therefore avoid destructive testing without advance notice, a documented protocol, and a meaningful opportunity for other parties to inspect or participate.

Computer Data

Computer evidence may contain both machine-generated information and information entered by a person. Each component requires separate analysis.

• Machine-generated data: Automatically created information, such as system timestamps, GPS coordinates, access logs, audit trails, and transaction data, ordinarily is not hearsay because it is not a statement by a person. Admissibility instead depends on authentication and evidence that the system was operating properly. (People v. Hawkins (2002) 98 Cal.App.4th 1428, 1449-1450; People v. Goldsmith (2014) 59 Cal.4th 258, 273-274.)
• Human-entered data: Notes, descriptions, classifications, and other information entered by a person may be hearsay when offered for their truth. Authenticating the database does not eliminate that objection. The proponent must establish an applicable exception, such as the business-records exception under Evidence Code § 1271.
• Mixed records: A single report may contain both categories. An automatically recorded login time may be nonhearsay, while an employee’s accompanying narrative remains a human assertion requiring a separate hearsay analysis.
• Printed and exported records: Evidence Code § 1552 creates a rebuttable presumption that a printed representation accurately reflects the computer information it purports to represent. The presumption establishes accurate reproduction, not the truth of the underlying information or the accuracy of the system, formula, or original data entry. (Ampex Corp. v. Cargle (2005) 128 Cal.App.4th 1569, 1573; Hawkins, supra, at p. 1450.)
• Qualified witness: A programmer, vendor representative, or forensic expert is not invariably required. A witness who understands the system’s general operation, knows how the report was obtained, and can explain the resulting data may provide sufficient authentication. In People v. Rodriguez (2017) 16 Cal.App.5th 355, an officer familiar with an electronic-monitoring system authenticated a GPS report without testimony from the software vendor.
• Foundation for a database report or spreadsheet: The witness should be prepared to identify:
  • The system and its ordinary purpose
  • Whether each material field was generated automatically or entered by a person
  • How the data was associated with the relevant person, device, account, or transaction
  • Whether the system operated normally during the relevant period
  • How the report was retrieved, queried, filtered, sorted, or exported
  • The date range, fields, search terms, filters, and time zone used
  • Any formulas, calculations, conversions, or manual edits
  • The system’s access controls, audit history, and procedures for correcting records
  • Whether the native data, metadata, and audit logs were preserved
  • Why the exhibit fairly and accurately represents the responsive data
• Rebutting the presumption: Evidence of a malfunction, inaccurate timestamp, unexplained discrepancy, improper calibration, altered formula, incomplete query, or conflict with native data may rebut § 1552’s presumption. The proponent must then prove accuracy by a preponderance of the evidence. In People v. Rekte (2015) 232 Cal.App.4th 1237, expert testimony and physical testing undermined the reliability of automated traffic-enforcement data, and the proponent failed to rebut that showing.

Preserve the native source and document every step used to create the trial exhibit. A clean printout may be easier to display, but the native data, audit history, query parameters, formulas, and export settings may become essential if completeness or accuracy is challenged.

Official Records

Authentication, judicial notice, and the official-records hearsay exception are separate issues. Proving that a document is an authentic government record does not make every statement within it admissible for its truth.

• Certified copies: Under Evidence Code § 1530, a properly certified copy of a writing in the custody of a public entity is prima facie evidence of the writing’s existence and content. Official seals and signatures may also be presumed genuine under Evidence Code §§ 1452 and 1453. These provisions address authentication, not hearsay.
• Official-records exception: To admit a record for the truth of its contents, the proponent generally must satisfy Evidence Code § 1280 by showing that:
  • The writing records an act, condition, or event.
  • A public employee made it within the scope of official duty.
  • It was made at or near the time of the act, condition, or event.
  • The sources of information and the method and time of preparation indicate trustworthiness.
• Government website records: When using a record downloaded from a government website, preserve the complete URL, access date, agency name, document identifier, and surrounding webpage. A witness who obtained the record may authenticate the download, but a certified agency copy is preferable when the record will be disputed. A government URL helps establish provenance but does not resolve hearsay objections.
• Judicial notice: A court may take judicial notice of the existence of a court filing, recorded instrument, regulation, or official act under Evidence Code § 452. It ordinarily may not accept reasonably disputable factual statements within the document as true. (Sosinsky v. Grant (1992) 6 Cal.App.4th 1548, 1564-1569; Herrera v. Deutsche Bank National Trust Co. (2011) 196 Cal.App.4th 1366, 1375.)
• Documents held by an agency: A private document does not become an official record merely because it was submitted to, filed with, or retained by a government agency. Each document requires its own foundation and hearsay exception. (Alvarez v. Jacmar Pacific Pizza Corp. (2002) 100 Cal.App.4th 1190, 1205-1207.)
• Police and agency reports: Separate a public employee’s observations from statements supplied by witnesses or other third parties. Timely observations made within the employee’s official duties may qualify under § 1280. A civilian witness’s statement requires an independent hearsay exception, even if accurately quoted in the report.
• Opinions, conclusions, and diagrams: Determine whether the public employee personally investigated the matter, was qualified to offer the opinion, and relied on competent and trustworthy sources. A conclusion or diagram based primarily on inadmissible third-party statements does not become admissible merely because it appears in an official report.
• Traffic collision reports: California traffic collision reports are subject to additional statutory restrictions and generally are not admitted as trial exhibits. Vehicle Code § 20013 provides that an accident report may not be used as evidence in a civil or criminal trial arising from the accident. The investigating officer may still testify to admissible personal observations and, if qualified, opinions, subject to the ordinary rules of evidence. (Box v. California Date Growers Assn. (1976) 57 Cal.App.3d 266, 270-271.)

For Caltrans or local-public-entity records, obtain a certified copy whenever possible and identify who created the record, when it was created, the employee’s official duty, and how the agency maintained it. A Public Records Act production establishes the document’s source, but not necessarily that a public employee created it or that every statement within it is admissible.

Hulburt Law Firm

At Hulburt Law Firm, we prepare every case with trial in mind, laying the foundation needed to admit critical evidence, establish what happened, and hold the responsible parties accountable. If you or a family member suffered a serious injury, call (619) 821-0500 or contact us for a free, confidential case review.

Conor Hulburt is a plaintiff’s trial attorney and founder of the Hulburt Law Firm in San Diego, California.