The shelves of pharmacies are full of pills, tablets, capsules, and liquids that are worth a lot of money, especially to addicts. So when more than 37,000 prescription pain pills vanish from handful of CVS stores, the authorities get involved.

The L.A. Times’ David Lazarus reports that the U.S. Drug Enforcement Administration and the California Board of Pharmacy are investigating the disappearance of prescription pain meds from four stores in California.

The DEA served the stores with warrants almost a year ago after learning about prescription drugs like Vicodin that were not present and accounted for.

The company now faces up to 2,973 separate violations of the federal Controlled Substances Act because its records don’t match the actual inventory of the drugs in question. CVS could be forced to pay upwards of $29 million in penalties for these possible violations.

A rep for the U.S. Attorney’s office tells Lazarus that CVS has yet to respond to a letter sent last month detailing all of the alleged shortages.

The DEA investigation has been going on since 2012, when a DEA investigator learned of missing hydrocodone pills from a store near Sacramento. A pharmacy worker at the store eventually admitted to her employers that she had stolen some 20,000 pills.

Checking the temperature of other stores in the region, the investigator looked through the records of other CVS stores in the area and found 16,000 pills missing from one CVS; 11,000 from another and two additional stores with around 5,000 missing pills each.

A rep for the drugstore chain tells the Times that the purpose of the ongoing DEA investigations is “assuring compliance with state and federal requirements for administrative record keeping related to invoices and inventory for controlled substances.”

Last year, Walgreens agreed to pay $80 million following a DEA investigation into larger-than-usual orders for prescription painkillers from certain Florida distribution centers and stores.

Subsequently released documents showed that some stores had dramatically increased their orders on painkillers like oxycodone, and that the DEA believed store management was ignoring that prescriptions were being filled to consumers with questionable motives, including some customers who had been previously arrested at these locations for drug offenses.

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