El Cajon

Nine high school students were arrested Friday after a sheriff’s deputy posing as a student bought marijuana from them, the San Diego County Sheriff’s Department said in a statement.

The deputy enrolled at Valhalla High School in the fall and purchased marijuana from the students on several occasions during a five-month period, the statement said. Each purchase was made during school hours, on school grounds, and was documented.

The students were arrested as they showed up for class Friday and were taken to Juvenile Hall, where they will stay until they appear in court, the statement said. Juvenile authorities decided before the arrests not to release the students to their parents, in an attempt to discourage other students from buying and selling drugs.

The Grossmont High School District requested the investigation in an effort to curb drug activity at the school, the statement said.

A similar operation was carried out at Poway High School at the same time, but the undercover deputy there was unable to make any purchases.

“It is believed the reason for this is because Poway High School has a very closely supervised curriculum and a very successful drug education program in place,” the statement said.