"What happens with these groups is they hit one area and move on to another area," said investigator Sheila Cannan.
Cannan said the Costa Mesa thefts are similar to thefts at a Huntington Beach Arco, where information was pilfered June 21 and 22.
The station is the latest in a growing number of Arco stations used by thieves to steal information from debit card users.
At the beginning of July, thieves placed devices over the outdoor debit card payment machines, captured card information and personalized identification numbers, then made phony cards to withdraw about $700 at a time.
Some victims reported up to three such withdrawals from their accounts before being notified by their banks.
"It had a brand new [device] with a brand new sticker on it and I thought 'Oh, they must have installed a brand new system,'" said John Collett, who had nearly $1,200 stolen from his account.
Investigators have determined another skimming device was on the machines at the Fair Drive site April 5-6, 9-10, and 17.
Police have not determined whether the latest thefts are connected with those in April involving two other Arcos in the city, Cannan said.
KELLY STRODL may be reached at (714) 966-4623 or at firstname.lastname@example.org.