Authorities have been looking for the suspects for more than a week and say they have two men in custody Tuesday night.
One suspect was arrested by Bensalem Police in Philadelphia early Tuesday evening.
Police say 24th District Police spotted a vehicle suspected in the crimes about an hour later in the Port Richmond section.
Police followed the vehicle to the 2100 block of Cumberland where the suspects fled on foot.
One of the suspects in the pickup truck was arrested, but a third suspect remains at large.
The first theft happened at 6 p.m. on Tuesday, February 25th at the Sears in the Neshaminy Mall. Police say a man cut the cable securing a display case full of jewelry, loaded the case into a shopping cart and left the store.
Police say a getaway driver was in a red pickup truck outside the mall. The theft suspect got into the passenger side of the truck and both men fled the scene.
Then on Wednesday, February 26th, police say a spinning jewelry display case was stolen from the K-Mart at 176 W. Street Road in Lower Southampton Township. Witnesses saw a red 'newer model' pickup truck leaving the scene. Police say the first two letters on the license plate were reported to be "ZC."
"Store security confronted them in the parking lot, and the one threatened him with a knife. And the gentleman with the knife told the other gentleman to go to the car and get a handgun," explained Lt. Lieber.
The handgun was never displayed, but the two made off with more than $20,000 worth of jewelry.
Authorities say the duo is responsible for nearly a half dozen similar crimes within the past couple of weeks.
The bandits struck for a third time on Thursday, February 27th at the Sears store in the Oxford Valley Mall. Police say they stole a spinning jewelry display case and fled in a pickup truck - described as red or orange. Again, the first two letters on the license plate were reported to be "ZC."
"They seem very similar and we think it is the same guys pulling the same jobs," said Lt. Lieber.
The total amount of the thefts is well over a $100,000.
Anyone with information that could help police apprehend the third suspect is asked to call Det. Mike Moretti at 215-633-3719.