The truck was packed with signed NFL auction items when it was stolen in Renton after a Saturday night gala and auction hosted by former Seattle Seahawk Marcus Trufant and his Trufant Family Foundation.
The truck was recovered Sunday morning near Maple Valley, but all the merchandise was gone.
The stolen items included signed Seahawk footballs, rookie trading cards, collages, photographs, bowling shoes, a bowling shirt, mini Seahawk helmets and a Jacksonville Jaguars mini helmet. All of the memorabilia was signed by Marcus Trufant.
Footballs signed by NFL players Brian Russell, Deion Grant, and Golden Tate were also taken, according to Renton Police.
Constance Trufant, who helps run the foundation, was asked Wednesday what she would say to the thieves.
"I would say you're a bad bad man or woman and that this is something really terrible that you did for a charity that's trying to raise money to benefit kids in the community and you should be ashamed of yourself," she said.
Police are asking sports memorabilia dealers, fans and collectors to call them if they suspect they're being offered any of the missing items.