Cal Fire arrested engineer Robert Hernandez on suspicion of committing arson on forest land in the areas surrounding Geyserville, Healdsburg and Windsor.

A Cal Fire firefighter was arrested Friday morning on suspicion of starting five separate wildfires in the state within the last six weeks.

Robert Hernandez, a 38-year-old fire apparatus engineer with Cal Fire, the state’s main firefighting agency, was arrested on suspicion of setting fires on forest land near the Northern California towns of Geyserville, Healdsburg and Windsor between Aug. 15 and Sept. 14.