Originally Posted by gsoltso

This type of occurrence is not without precedent. There have been times where individuals and local leadership have worked to return items to someone, after it was not allowed through the checkpoint area. It is not the norm, nor its it something that I anticipate seeing frequently - but there have been incidents similar to this before.

My $.02, an empty shell casing may need additional scrutiny to make certain it is indeed just an empty casing, but we have seen these many times before. Sometimes they are part of a necklace worn, sometimes they are part of a memento box. I am not certain what was happening here, but the TSA What Can I Bring App returns the following result:

Ammunition

"Empty Shell Casings are allowed in carry-on bags, as long as the projectile is no longer intact"