A dozen people have been indicted in Boulder County over an alleged scheme in which credit and debit card information was stolen from 7-Eleven and other convenience store locations using card skimming devices.

The indictment was filed in March, but the Boulder County DA’s office issued a news release Tuesday announcing the charges.

Following an extensive investigation from the Lafayette Police Department and the Colorado Bureau of Investigation, 11 adults and one juvenile have been charged with violations of the Colorado Organized Crime Control Act, along with other charges including cybercrime, identity theft, theft, attempted theft, possession of identity theft tools, possession of forgery devices, criminal possession of financial devices and evidence tampering.

As of Tuesday, eight people charged in the scheme have been arrested. They include: Romario Ciuciu, 26; Viorel Tudor, 29; Ion Ciuciu, 49; Felicia Ciuciu, 48; Denisa Barbu, 24; Ana Maria Dumitru, 25; Madalina Velcu, 21, and the juvenile.

The group allegedly stole financial information using card skimming devices installed on ATMs and sales machines located at convenience stores in the Front Range, particularly 7-Eleven stores. The devices used would record the card information and PINs from cards and create a clone of the card to steal money from the victims.

Hundreds of people had their card information stolen over about six months, the release said. This included 447 Colorado EBT cards. In total, the group is accused of stealing or attempting to steal about $301,400 from victims, according to the news release.

The devices were hard to detect and many of the victims were unaware their information had been compromised.

Shannon Carbone, a spokesperson for the Boulder DA’s office, advised people to look for scratches near the card terminal and PIN entry plates, which may indicate if a machine had been tampered with.

Carbone also recommended using machines that have a tap-to-pay feature rather than a chip insert or swipe. She also recommended covering the PIN pad when entering your PIN.

“Over the past few years, the Lafayette Police Department has repeatedly connected seemingly unrelated offenses to major crime operations to bring them to a halt,” Boulder DA Michael Dougherty said in the news release. “Their work has improved public safety across the metro area.”

The Denver Gazette reached out to 7-Eleven officials for comment, but did not receive a reply by the time this story published.