In the world of digital evidence, chain of custody is sacred. But what happens when that chain is broken—by the very agency entrusted to uphold it? This case, still ongoing, reveals how metadata manipulation, improper access, and lack of write-blockers threatened to undermine not just the evidence, but the integrity of the entire investigation.
Narrative Summary
Tampering in Plain Sight
A Canon CF card was imaged twice. The second image, created by last minute replacement for the first CART Examiner, contained roughly 37 additional images that weren’t present in the first. The original card had been signed out to a non-CART SSA (Supervisory Special Agent)—a direct violation of FBI policy. The card was accessed without a write-blocker, causing timestamp changes and introducing the potential for other altered metadata or file system changes. And when challenged? The argument wasn’t that it didn’t happen—it was that it didn’t matter.
As metadata was critical to the prosecution’s case, the initial CART Examiner had previously testified that since metadata could easily be edited, it was not reliable. He could hardly testify to the opposite of that in this case, so he was reassigned to Africa just days before the trial. The replacement CART Examiner testified that the metadata was reliable, as it was difficult to change or edit.
What the Logs Reveal
Behavioral Patterns in the Clusters
Canon writes image data to CF cards in a fast, burst-optimized pattern that’s predictable—until it’s not. Windows, by contrast, writes in a way that favors recoverability. That distinction allowed us to identify that the card had not just been accessed, but manipulated. When cluster behavior doesn’t align with the device’s expected write pattern, questions must be asked—and answered.
The Team Effort
Experts United, Silenced Voices
While I mapped the write pattern discrepancies, others—former FBI CART Examiners and “insiders”—handled other data discrepancy issues and the policy side. Together, we built a comprehensive narrative. And yet many experts who reviewed the evidence and acknowledged the obvious anomalies and tampering, refused to testify or even comment, citing fear of reprisal or conflicts with federal contracts. This silence speaks volumes.
Why It Matters
Beyond One Case
The presiding judge refused to grant the motion to review the original data, the CF Card, stating the defendant would have been found guilty regardless. But had the alteration been openly acknowledged in court, it could have tainted the entire investigation and cast doubt on all related evidence. This isn’t just about one case—it’s about ensuring the rules apply equally to everyone. That’s justice. That’s integrity.