San Mateo County law enforcement officials cited 19 stores last weekend during an underage tobacco sales sting, according to the sheriff's office.
Deputies worked with police in Millbrae, Daly City and San Bruno to target 181 tobacco sales outlets on Sunday, the sheriff's office said.
Nineteen stores sold tobacco to underage decoys -- including some places with a history of multiple documented illegal sales.
In general, though, stores in neighborhoods that had been hit by a similar sting last year were less likely to sell to the decoys, the sheriff's office found.
"It looks like regularly funding enforcement of the law has a real effect on stopping illegal sales of tobacco to young people in San Mateo County," Deputy Jerry Justice, who coordinated the sting, said in a statement.
Last year, 35 percent of the stores inspected in Daly City sold tobacco to a minor decoy, the sheriff's office said. This year, only 6 percent did.
Millbrae stores also sold to decoys 20 percent of the time last year compared to 7 percent this year.
In areas that had not been targeted for several years, decoy sales rates were as high as 28 percent, the sheriff's office said.
The decoys were also able to successfully "shoulder tap" adults outside the stores and ask them to buy cigarettes.
Three out of six times a minor decoy approached an adult outside, the adult agreed to buy cigarettes for the youth, the sheriff's office said.
-- Bay City News