Original Evidence

Original evidence refers to images and videos that are either seized directly by law enforcement or provided by other individuals or sources. These materials are preserved in their native state to ensure authenticity and integrity, and are used to demonstrate the evidence presented before the courts.

All original evidence is subjected to forensic examination, during which metadata is extracted and analyzed. This metadata may include details such as the file format, video container, creation date, device used, and other technical attributes. For videos, the container format (e.g., MP4, AVI, MOV) is identified, while for images, the image format (e.g., JPEG, PNG, RAW) is determined.

As part of the analysis, the benefits and limitations of each format or container are assessed. This may relate to aspects such as compression, quality retention, compatibility with forensic tools, or the ability to preserve metadata. Understanding these characteristics is crucial in evaluating the reliability and admissibility of the evidence in a legal context.

Use of Demonstrative Charts for Comparative Analysis

I utilize demonstrative charts to articulate the similarities and differences between observable elements—such as clothing, body features, and other identifiable items—found in video or image evidence. These elements are visible to the trier of fact, yet are not independently submitted as evidence. I refer to these as “unknown items.”

These unknown items are compared against “known items,” which consist of physical evidence or photographs formally submitted to the court. This comparative process helps to assess whether the unknown and known items share characteristics that may support or challenge their association.

As part of this process, I take into account the video file’s container format and the codec used to compile the original video. This ensures that any visual artefacts or compression issues introduced by the format are understood during analysis. I then determine the most suitable frame from the video to export for comparative purposes. This frame, referred to as the unknown image, becomes the basis for visual comparison with the known item.

The demonstrative chart presents:

• • The source and context of each item (unknown vs. known),

  • The methodology used for selecting frames and images,

  • A side-by-side comparison outlining key similarities and differences,

  • And any relevant observations about image quality or limitations.

This chart is presented to the trier of fact to assist in evaluating the probative value of the evidence and to determine what weight—if any—should be attributed to the visual comparison.

Below is a single entry of a court chart: