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Citizen Submitted Video

Law enforcement investigators are hard pressed to find a crime that doesn’t involve digital image or video evidence. Aside from playing an integral role in investigations, this visual evidence is often key to criminal prosecutions.

While image and video evidence can be tremendously impactful in the criminal justice system, the acquisition, analysis, and management of these files have challenged law enforcement for years.  New technology and platforms have been introduced to allow for citizens to submit images and video files through web portals, making it easy for law enforcement to acquire, review, and manage submissions in a fast and efficient manner. 

Although these technologies allow for easy file sharing, they present unique challenges in handling visual evidence, primarily with the authentication of video files for use in investigations and legal proceedings, as well as for the review of large volumes of submitted evidence.

Citizen submitted video

Police officers are regularly tasked with obtaining visual evidence of crimes. This evidence can range from cell phone recordings to videos captured by home security systems such as Ring and Nest cameras. Recently, public evidence submission portals allow for officers and investigators to send upload links to individual citizens via email or text message. These upload links, tied to a case number created by the officer, allow for the citizen to select an image or video from their device and submit it through a web browser to a secure file storage system. Law enforcement then has the ability to review, store, and share the video for use in investigations and prosecutions.

Additionally, for use on a case-by-case basis, public evidence submission portals may allow for agencies to solicit citizen submitted video in response to large scale or critical incidents. Instead of sending a specific upload link to individual citizens, agencies can create and disseminate a public web link where anyone with the link can submit images and videos for police to review.

The use of public evidence portals to obtain visual evidence has proven to be an efficient method to easily obtain video and image evidence from citizens. No longer does a victim or witness need to relinquish their phone to law enforcement to acquire evidence. Files are securely transmitted and stored for review and dissemination. Public evidence submission links serve to increase community engagement and may lead to the receipt of evidence that would previously not have been available. Due to their ease of use, efficiency, and security, public evidence submission portals will be standard in obtaining citizen images and video today and in the future.

Although a great solution for obtaining image and video files to law enforcement, public evidence portals present unique challenges when handling submitted files. In a departure from current approaches, law enforcement does not have access to the submitting device or original evidence. The submitted file may be deleted from the citizen’s device after submission and may even be submitted anonymously. When opening a public submission portal, agencies have been inundated with non-pertinent videos (anime, cat videos, etc.) in order to overwhelm investigators, resulting in the need to stop accepting submissions.

The lack of the ‘original’ file presents significant challenges when authenticating submitted video files, particularly in identifying if that file has been edited or trimmed prior to submission. Recent research has found that video files recorded on iOS devices and transmitted through a public evidence portal are not consistent with the original video file found on the device. Due to the change in the video file’s metadata and, in some cases, visual appearance, these video files become extremely difficult to authenticate with current approaches that rely on metadata and pixel values. Since these challenges have come to light, law enforcement agencies have been cautioned against the use of public evidence submission portals to acquire evidentiary video.

The challenge

Our findings

At Medex Forensics, we have looked into the changes that occur when video files have been transmitted to public evidence portals. We have found that the changes are not actually attributed to the public evidence portal, but to interaction between the OS on a cell phone that is storing video and the mobile browser application used to transmit the file to the portal. This behavior has been seen across various iOS devices as well as certain Android phones. These changes may also make it appear that a video file is consistent with a camera original file, however the file is absolutely not the same as found on many devices, and can even be edited on the device prior to submission but appear, at face value, to be an original video.

Since law enforcement may not have ever had access to the original video file (which may have since been deleted), the changes to the submitted video and metadata create significant authenticity challenges to the introduction of these files in court. Currently, public evidence portals lack the technology to effectively identify editing of a video’s content, or proving authenticity of files due to the changes during the submission process. These challenges leave agencies faced with a dilemma – balancing the efficiency and effectiveness of citizen submitted video with the burden of only using accurate evidence in investigations and introduction in court.

Since the Medex video authentication and source identification platform does not rely on pixel values or descriptive metadata, it is possible to authenticate citizen submitted video to show that the visual display has not changed. It is also possible to quantitatively detect editing by popular editing tools or when edited on a cell phone prior to submission. This non-content based approach allows for the benefits of citizen submitted video files to law enforcement while still effectively evaluating authenticity of those files. When deployed with a public access link during a large incident, Medex can also identify camera-original video files, aiding in triaging those videos most likely to contain evidence and actionable leads.

The solution


Medex Forensics provides examiners the newest automated tools for digital video authentication, source detection, and provenance analysis. Medex’s patent-pending approach to examining digital video provides investigators and prosecutors new insight into digital video.

To learn more about how Medex can enhance your daily workflows, contact our sales team at

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