Investigators are trying to determine if they were stealing information from customers at a West Covina gas station near the location where they were arrested.
Police say devices had been placed inside three gas pumps, designed to relay debit card information by radio to a nearby vehicle.
"These skimming devices in these gas pumps capture account numbers and pin numbers as the customers purchase gasoline. Then they use this information to make these counterfeit credit cards," said Rudy Lopez of the West Covina Police Department.
This type of theft does not apply to credit cards where you have to enter a zip code.
The two suspects, Arman Avanesyan and Raghi Khajemtourian, allegedly had blank credit cards encoded with valid bank account information and $6,000 in twenty-dollar bills.
Investigators believe the men withdrew the cash at ATM machines using the fake cards.