Body Camera Footage Chain of Custody: What Defense Attorneys Need to Know

Your client was arrested. The responding officers were wearing body cameras. In discovery, you receive a link to download 12 hours of body camera footage. You click the link, download the files, and begin your review.

At that moment, the chain of custody is broken.

The files are now on your hard drive, or in a shared folder, or attached to an email you sent to your paralegal. No system is tracking who has accessed them. No hash verifies they haven't been altered. If your expert witness reviews the footage, there's no log of when they accessed it or from what device. If opposing counsel later claims the footage was edited, you have no contemporaneous documentation to prove otherwise.

This is the reality for defense attorneys handling body camera evidence in most jurisdictions across the country. The agencies that record the footage have chain of custody. The platforms they use (most commonly Axon Evidence) have access logs. But the moment that footage leaves the agency's system and enters your hands, the documented chain ends.

The Scale of the Problem

Body camera adoption has reached near-universal levels in American law enforcement. According to the Bureau of Justice Statistics, over 80% of general-purpose law enforcement agencies had acquired body-worn cameras by 2022, and deployment has only accelerated since.

Jefferson County, Colorado, a single jurisdiction, reported 67,700 body camera videos comprising 41,000 hours of footage in 2025. Large urban departments generate even more. Every one of those videos is potential evidence in a criminal proceeding, and the defense is entitled to review them.

How the defense receives and manages that footage varies wildly by jurisdiction. Some districts provide access through Axon Evidence's sharing portal. Others send download links that expire after 30 days. Many still burn DVDs; a 2023 survey found that more than 40% of agencies still distribute evidence on physical media despite having cloud-based systems.

Each of these methods has the same fundamental problem: once the defense downloads the footage, there is no continuing chain of custody.

What Chain of Custody Means for Video Evidence

Chain of custody for digital evidence requires documentation of every person who accessed the evidence, when they accessed it, what device or system they used, and what they did with it. For video evidence specifically, courts look for:

Integrity verification. Proof that the video has not been altered since it was collected. For digital files, this is established through cryptographic hashing: computing a SHA-256 hash at the point of collection and verifying the same hash at every subsequent stage. If the hashes match, the file is mathematically identical. If they don't, the file has been modified.

Access documentation. A log of every person who viewed or interacted with the evidence, with timestamps and identifying information. This is particularly important when footage is shared with expert witnesses, co-counsel, or investigators. Each additional viewer is a potential point of challenge.

Authentication readiness. Under FRE 901(b)(9) and 902(13), the proponent of digital evidence must be able to describe the process or system used to manage the evidence and demonstrate that it produces accurate results. If your evidence management process is "I downloaded it and put it in a folder," that description does not satisfy the standard.

The Axon Problem

The majority of body camera footage in the United States is managed through Axon Evidence (formerly Evidence.com). When an agency provides defense access through Axon, the defense attorney typically receives a sharing link through Axon Evidence's portal.

This system has several practical problems for defense counsel:

Time-limited access. Many agencies configure sharing links to expire after 30 days. If the defense needs to revisit footage six months into a case, which happens regularly in complex criminal matters, the link is dead and they must request re-sharing. The original access logs are no longer available to the defense.

EULA requirements. Axon requires users to agree to its End User License Agreement before accessing shared evidence. Some defense attorneys have raised concerns about agreeing to a private company's terms as a condition of accessing their own client's evidence.

No defense-side chain of custody. Once the defense downloads footage from Axon, the Axon access log records the download, but nothing beyond it. The defense's subsequent handling of the footage is undocumented. If the defense shares the footage with an expert, sends clips to co-counsel, or creates working copies, none of that is tracked.

Single-format dependency. Axon exports footage in specific formats that may not be compatible with the defense's review tools. Converting or transcoding the footage raises potential authentication challenges if the conversion process is not documented.

The result is that defense attorneys often end up with body camera footage on a personal hard drive, in a Dropbox folder, or attached to email threads, with zero documented chain of custody from the moment of download forward.

What Happens When Chain of Custody Fails

The consequences of a broken chain of custody for video evidence depend on the context, but they follow predictable patterns:

Authentication challenges. Opposing counsel moves to exclude the defense's copy of the footage, arguing it cannot be authenticated because the chain of custody is broken. Even if the motion fails, defending it costs attorney time and creates uncertainty about the evidence's admissibility.

Tampering allegations. If the defense offers footage that appears different from what the prosecution has, even if the difference is due to format conversion or playback settings, the broken chain of custody makes it impossible to prove the footage wasn't altered. The defense bears the burden of proving the footage is what it purports to be. This is the same vulnerability that the defense exploited in State v. Casey Anthony, where challenges to digital forensic methodology undermined the prosecution's entire digital evidence case.

Expert testimony vulnerability. If a defense expert's opinion is based on footage that cannot be authenticated, the expert's testimony may be challenged under Daubert. The foundation for the opinion is the footage; if the footage is questionable, the opinion built on it is questionable.

Leak attribution. In high-profile cases, body camera footage has been leaked to the media. When footage leaks and the chain of custody is undocumented, it becomes impossible to identify the source. This creates serious ethical exposure for the defense team, particularly if the leak appears to have originated from defense-side access.

A Practical Chain of Custody Workflow

For defense attorneys handling body camera evidence, a defensible chain of custody workflow has five elements:

1. Hash on receipt. The moment you download body camera footage, whether from Axon, a DVD, or a file transfer, compute a SHA-256 hash of every file. Record the hash, the filename, the file size, and the timestamp. This becomes your baseline. Any future verification compares against this hash. If you're using a system that computes hashes automatically at upload, this is handled for you. If you're managing files manually, use a command-line tool (sha256sum on Linux/Mac, certutil on Windows) and document the output.

2. Centralize storage. Do not distribute body camera footage across personal devices, email threads, and cloud folders. Store it in a single system that logs every access. When your paralegal needs to review footage, they access it through the system, not through a copy you emailed them. When your expert needs to review footage, you share it through a tracked link, not a USB drive you hand them in a parking lot.

3. Log every access. Every person who views the footage should be logged with their identity, the time of access, their IP address, and their user agent. This creates a complete record that you can produce if the chain of custody is challenged. It also protects you; if footage leaks, the access log identifies every person who had access.

4. Watermark shared views. When footage is shared with expert witnesses, co-counsel, or investigators, each viewer should be individually identifiable in the event of a leak. Visible watermarking, which embeds the viewer's identity in the video frame, creates attribution that survives screen capture. If a clip appears on the news, the watermark identifies who had access to that specific copy.

5. Generate documentation. Before offering body camera evidence at trial or in a motion, generate a written record of the chain of custody: when the footage was received, the original hash, every access that occurred, the current hash (confirming integrity), and a certification under 28 U.S.C. § 1746 attesting to the process. This is your FRE 902(13) certification, and it should be prepared well in advance of any evidentiary hearing.

Preparing for the Authentication Hearing

When body camera footage is offered into evidence, the court will evaluate its authentication under FRE 901. With a proper chain of custody in place, the authentication process is straightforward:

Produce the certification. Under FRE 902(13), a written certification describing the system and attesting to its accuracy can self-authenticate the evidence without a foundation witness. The certification should describe the hash computation, the access logging, and the integrity verification process. The Lorraine v. Markel opinion established why this documentation is essential; courts will not simply accept that a video is authentic without affirmative proof.

Produce the access log. The log demonstrates that every interaction with the evidence is documented. It shows who accessed the footage, when, and that no unauthorized modifications occurred.

Produce the hash verification. A comparison of the original upload hash against the current hash proves the footage has not been altered. Under SHA-256, if the hashes match, the files are identical, a comparison that cannot be credibly disputed.

An attorney who arrives at the authentication hearing with this documentation has an evidence package that is resistant to challenge. An attorney who arrives with "I downloaded it from Axon six months ago and it's been on my hard drive" has a problem.

The Volume Challenge

The practical difficulty with body camera evidence is not authentication theory; it's scale. A single arrest involving four officers with body cameras can produce 8–12 hours of footage. A complex criminal case can involve hundreds of hours.

Managing this volume requires a system, not a process. Manual hashing, manual access logging, and manual chain of custody documentation become unworkable at scale. Purpose-built evidence management tools automate the integrity verification, access logging, and certification generation that would otherwise require hours of paralegal time per case.

The investment in a systematic approach pays for itself on the first case where authentication is challenged. A foundation witness to authenticate video evidence costs $3,000 to $5,000 per appearance. An authentication challenge that requires briefing and a hearing costs $2,000 to $10,000 in attorney time.

Conclusion

Body camera footage is central to criminal litigation. Defense attorneys receive this evidence regularly but rarely receive the chain of custody documentation that the producing agency maintains internally. That gap is where authentication challenges, tampering allegations, and leak attribution failures originate.

Closing that gap requires hash verification on receipt, centralized and logged storage, individually watermarked sharing, and FRE 902(13) certification prepared before trial. Failure to maintain a proper chain of custody exposes your evidence to the same spoliation challenges documented in the major spoliation cases not because evidence was deliberately destroyed, but because the process for preserving it was inadequate from the start.