The galled goldsmith

Jack’s value in jewellery stores was proving to be a new frontier for his agency.

Mr. Goldstein walked into the agency with a case. 

“To be very honest, I already hired Ernie, another detective.”

“He came to me about a few hours after the robbery and explained he was going door to door for a new case. I told him I did have a case.”

Mr. Aurelius Goldstein explained. 

“I was in charge of keeping our town, Oliver Harrison’s gold medal from the 2004 games. Then, it was stolen.”

“Ernie found it for me, but I remember the medal had a bent corner. Now, the bent corner is gone.”

Jack politely asked for the medal, and in his garage-turned-lab tried to bend a corner of it. 

It didn’t bend.

Five minutes later, Ernie was being challenged by Jack.

“You’re the stealer of the medal!”

WHY?

Because Gold is very malleable and will bend if you apply pressure.