ACWORTH — More victims have come forward saying money was stolen from their bank accounts after using their debit cards at local gas stations since a California man was arrested a month ago on fraud and theft charges.

Akop Taymizyan of Glendale, Calif., has been behind bars at Cobb County Jail since he was arrested on Nov. 4 by Cobb Sheriff’s investigators on charges of card fraud-financial transaction, identity fraud and violation of the RICO Act, all felonies. Though he has declined to speak with investigators, several crime victims have been cooperating.

Col. Milton Beck said the sheriff’s office has been in touch with victims who say they used their debit cards and personal identification numbers at gas station pumps, only to find out later that hundreds of dollars were missing from their bank accounts.

Beck said he expects 18 to 20 more victims to be identified.

“How many more victims, I couldn’t tell you right now, but there are several possible victims they’re still looking into,” Beck said. “You’ve got to confirm some things and get official documents. There’re photographs that are going to be involved at ATM machines to confirm that this is the same individual, so once those are confirmed you’ll probably see more charges coming.”

Investigators connected 35-year-old Taymizyan to the fraud activity by conducting surveillance on a series of ATM locations.

According to one warrant, he was photographed in late October at BB&T ATMs in Dunwoody and Sandy Springs, where he withdrew a total of $1,500 in three separate instances, using the debit card of an Acworth woman.

Taymizyan, a Russian native and naturalized U.S. citizen, is accused of stealing thousands of dollars by collecting private financial data from gas pumps. He allegedly used the PINs he obtained to withdraw cash at ATMs. The common denominator was that the victims used their debit cards at gas pumps.

“We believe he was utilizing skimmers,” Beck said.

Card “skimming” is becoming increasingly popular amongst criminals, making it a billion-dollar industry, according to banking industry data. To get the data, criminals attach a card skimmer over an actual card reader on an ATM or other place where debit or credit cards are swiped. Information from the device, which records account numbers and access codes of unsuspecting victims on its magnetic strip, can later be retrieved from the device or transmitted.

Skimmers can’t easily be seen on the readers, Beck said, so most people swiping their cards would not realize something was amiss.

Skimming can occur at ATMs, restaurants or stores, as well as card-activated gasoline pumps. According to the sheriff’s office, gasoline pumps across the county were targeted. Authorities are investigating similar transactions in Texas, Nevada and California, Beck said.

Investigators suspect Taymizyan drove from to Georgia from California and was staying in a hotel, where he possibly received assistance from other individuals.

“This has been going on not just in Georgia, but in other states also,” Beck said. “We think it’s several individuals involved with this.”

Sherri Scott, a spokeswoman for Vinings-based RaceTrac, which has been linked to many of the local thefts, said her company has been working with the sheriff’s office. She said RaceTrac will be installing security decal stickers, which can reveal tampering, on pumps at all of its stores by the end of the year.

“The roll-out of the security decals was planned before these alleged incidents took place,” she said. “Data theft prevention is a big issue for all retailers. We have an internal task force that’s been charged with addressing this and figuring out the best way to protect our guests.”

Taymizyan is being held without bond. His lawyer, Atlanta attorney Bruce Harvey, did not respond to a request for comment.