RIVERSIDE (CBSLA) — Nearly 800 paper files containing sensitive information were stolen last month from a Riverside County employee’s vehicle, the county announced Thursday.

The records, stolen July 27, contained sensitive information about cases investigated by the Riverside County Department of Public Social Services, putting the personal data of 770 individuals at risk of misuse, officials said.

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“We don’t know who stole the records or for what reason,” Sarah Mack, director of DPSS, said in a statement. “However, we do know this breach represents a concern to each individual whose records were taken, and we are determined to help minimize the privacy risks that may arise from this unfortunate incident.”

According to a statement posted on the department’s website, a supervisor for DPSS Adult Protective Services was transporting the closed-case files from a Palm Desert sheriff’s substation to Riverside for archiving. The Riverside Police Department is conducting an active investigation. The incident is also under administrative review, the statement said.

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The stolen files contained reports of elder or dependent adult abuse and included clients’ full names, addresses, dates of birth and social security numbers. DPSS said the 770 stolen files — mostly relating to reports filed in the greater Coachella Valley region— represented a “tiny fraction” of the roughly 1.5 million client records the agency handles annually.

“We apologize to each affected person,” Mack said. “Protecting sensitive client information is a priority for this organization and we want to ensure that best practices are maintained by all employees at all times,” Mack said.

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Those who believe they might be impacted or want to know if they have been can call 951-358-3010 between 8 a.m. and 5 p.m. Monday –Friday.