Paul A. Farnsworth, a 61-year-old Cabrillo Unified teacher and coach of nearly three decades, was arrested Thursday at his home in Half Moon Bay on allegations he sexually abused a former student beginning in 2008 — and San Mateo County detectives say they believe there are other victims who have not come forward.

The arrest reads on its face as a single blotter item, but the details released by authorities describe something a coastal community will sit with: a longtime, trusted district employee whose job placed him in both elementary classrooms and a high school athletics program, facing an allegation dating to 2008 that reached investigators only this month, with detectives publicly signaling they expect more people to step forward.

Paul A. Farnsworth spent nearly three decades inside Cabrillo Unified schools — teaching grade-schoolers at El Granada Elementary and coaching teenage runners at Half Moon Bay High. On Thursday, the 61-year-old was taken into custody at his home in Half Moon Bay, accused of sexually abusing a former student beginning in 2008, and San Mateo County detectives say they believe there are other victims who have not yet come forward.

The arrest is, on its face, a single breaking-news blotter item. But it describes something a coastal community will have to sit with: a longtime, trusted district employee whose job gave him access to children across the age spectrum — from elementary classrooms to a high school cross-country team. The alleged abuse dates to 2008; the report reached the Sheriff's Office only this month, and investigators have publicly signaled they expect more people to step forward.

Detectives with the San Mateo County Sheriff's Office opened the investigation in early August, after a woman came to the agency for the first time to report that Farnsworth had abused her in 2008, during the season he served as her coach, as KTVU first reported↗ (external source, opens in a new tab). She told investigators that roughly a year later, when she was 16, the two entered into a sexual relationship.

Detectives had obtained an arrest warrant, and on Aug. 13 they took Farnsworth into custody at his residence and booked him at the county's Maguire jail in Redwood City. He was booked on two documented felony counts: one alleging lewd conduct with a 14- or 15-year-old, the other alleging forcible sexual penetration. (The Sheriff's release is headlined with a broader count, but the two charges above are the ones documented at booking.) Online court records reviewed by the Half Moon Bay Review↗ (external source, opens in a new tab) showed a judge set bail at $150,000, with arraignment scheduled for Friday afternoon; several documents in the case are sealed.

What distinguishes this case from a routine arrest is the breadth of access the allegations describe. Farnsworth had worked in Cabrillo Unified schools for decades — in elementary classrooms at El Granada, across grades three to five, and as a coach of the cross-country and track teams at Half Moon Bay High, according to the district and the Sheriff's Office. The district spans the Coastside from Montara to Half Moon Bay and includes Cunha Intermediate School and several elementary campuses.

The Sheriff's Office was unusually direct about the possibility of more people affected, saying the nature of the case led investigators to believe other victims, or people with useful information, had yet to be identified — and that it wanted to hear from anyone abused as a minor. Detective N. Pitts is taking information at 650-363-4060 and npitts@smcgov.org; the office is separately fielding anonymous tips at 1-800-547-2700.

The school district learned of the investigation on Aug. 12, placed Farnsworth on leave that same day, and only afterward learned he had been arrested, CBS Bay Area reported↗ (external source, opens in a new tab).

Superintendent Dr. Ramon Miramontes called the news "deeply concerning" for what he described as a "close-knit community," said in a prepared statement that the district was working with law enforcement, and pledged to keep families informed as the case proceeds.

Miramontes said the district would make counseling available to students and framed the protection of children as a collective duty, urging staff and families to raise any concern about a student's well-being through official channels.

None of the allegations has been tested in court, and Farnsworth is presumed innocent. But the Sheriff's appeal is a reminder of a pattern that recurs in these cases: abuse alleged to have happened inside a school's orbit, disclosed years later, and only then raising the question of who else may have been in that same orbit.