Hi Chuck,
It's unclear to me what the problem is. The walkthrough says:
Victim's body - Hanged man: The cognition vision shows that the man was dropped on top of a dragged table.
Table: The cognition vision shows a circular artifact on the table. Erica's visions are getting out of hand.
Blood on wall: The cognition vision shows the circular artifact from the table kicked off and rolled under the shelf at right.
Graffiti: Erica says she will check it tomorrow when the others are gone.
Go to and check under the shelf. Get the antique artifact.
It sounds pretty straightforward. Let's wait for another player who might be able to help you. If no luck with that, maybe we can find a video walkthrough.