Officers on the Modesto Police Departments Crime Reduction Team on Saturday arrested six people during a so-called decoy shoulder tap operation aimed at adults who purchase alcohol for people under 21.
Officers had decoys stand outside seven stores.
The decoys told people they were under 21 and asked them to buy beer for them. Of the 17 people asked, four purchased beer for the minors and were arrested.
Two additional subjects were arrested on warrants.
The penalty for furnishing alcohol to a minor is a minimum $1,000 fine and 24 hours of community service.