The robbery happened around 11:20 a.m. Tuesday at Helzberg Diamonds.
Police say the suspects smashed a case and made off with $10,000 worth of jewels.
According to Montgomery Township Police Lt. William Peoples, it was a textbook smash-and-grab robbery.
"The way they're moving and organized and the equipment that they have, they're in and they're out - and no hesitation. I would say it's not their first time," Peoples told Action News.
In fact, the trio was so prepared for the break-in, they had a special kind of hammer to break the shatter-proof showcase glass.
"It's not a regular hammer. It's called a maul, which is kind of like a mini sledgehammer, a cross between a hammer and sledgehammer," Peoples said.
Luckily, no employees or customers were hurt.
"The employees were off to the right hand side," said Peoples. "The one took cover under the desk. The other went back to the storeroom area."
There's another reason why Peoples thinks this isn't their first time: the suspects apparently scouted out the mall and knew exactly how to get in and out undetected.
"There's construction going on," he said. "There's a back door open. It typically wouldn't be known by most people."
The store was closed for the rest of the day, but the rest of the mall remained open as the search for the suspects continues.