The man in dark jeans and a black windbreaker sat on a folding chair near the back of the San Mateo County Event Center. He sported an earpiece and wore a blue surgical mask that obscured much of his face.
His presence may have gone unnoticed if not for the event that had just taken place there: the International Gem and Jewelry Show.
It was a little after 5 p.m. on July 10, and the expo had ended. Dozens of exhibitors were packing up the contents of their glass showcases, which sparkled with jewelry worth tens of millions of dollars. At that point in the day, only authorized personnel were allowed inside the exhibition hall, so the man drew the suspicions of Brandy Swanson, the show’s manager and a self-professed “mama bear” who looks out for the event’s vendors.
