The frozen food section of a grocery store in Gualala, Calif., on April 6, 2023. In San Mateo, police are alerting residents to a self-checkout scam targeting elderly shoppers by secretly charging extra items to their cards.

The San Mateo Police Department is alerting residents to a troubling scam unfolding at self-checkout aisles in local retail stores, one that often targets elderly shoppers.

In an advisory Wednesday, the department said the scam starts with a seemingly friendly interaction. The suspects approach their victim inside the store, strike up a conversation, and gradually build trust. They then ask for help paying for essential items like food, medicine, or childcare products. 

While the victim is distracted during the checkout process, the suspects secretly scan and charge multiple other items using the shopper’s payment card without knowledge of the victim, police said.

“This scam commonly involves the targeting of elderly victims and involves suspects working in pairs,” the department said.

Police are urging anyone who believes they or someone they know may have been a victim of this scam to come forward.

“We ask our community members to stay alert and protect yourselves, finances, and property,” the department said. “We encourage reporting crimes and suspicious activities. If you see a suspicious person, vehicle, or activity, call SMPD.”

The department did not indicate how many cases have been reported.