Employees at Santa Clara and Wilcox high schools discovered shattered windows on March 31 and contacted police.
On April 16, investigators learned that at least seven other high schools in the county had been similarly vandalized around the same time.
Officers arrested Jared Michael Brobst, 18, and a 17-year-old boy on April 26. Brobst was booked into Santa Clara County Jail and is facing vandalism charges. He is scheduled to be arraigned in Santa Clara County Superior Court on May 10.
The boy, whose name was withheld by police because he is a juvenile, was cited on several counts of felony vandalism and released to an adult, police said.