"It's just a shock and awe, where they come in, hit the cases, use intimidation or use, in this case, as in several cases, pepper spray," said LAPD Lt. Paul Vernon.
It's the latest in a string of smash and grab robberies in the Los Angeles jewelry district. There have been eight in that area this month alone.
In the most recent case, they got away with about $7,000 worth of costume jewelry and escaped in a waiting getaway car.
Investigators believe these crimes are motivated by the rising price of gold.