PALO ALTO (CBS SF) — A Palo Alto High School science teacher has been arrested for committing sex crimes against one of his students after the end of the school year, authorities announced Thursday.

Authorities said 46-year-old Ronnie Farrell of Palo Alto had been booked into the Santa Clara County Jail on four felony charges: child molestation, sexual battery, communicating with a minor with the intent to commit a sex crime, and arranging a meeting with a minor with the intent to commit a sex crime.

Investigators said that on Monday about 8:44 p.m. the dispatch center received a call from a parent reporting that their 15-year-old daughter had been assaulted by a teacher.

The victim had recently completed ninth grade at Palo Alto High School and the suspect had been her biology teacher.

The investigation revealed that the suspect had been communicating with the teen using private messaging on social media networks.

The suspect allegedly asked the victim to meet him at Palo Alto High School on Tuesday, June 7, at 9:00 a.m. It was normal for the teen to help her teachers with chores and such in the classroom so she agreed to meet him.

The suspect led the victim to his classroom, where the two of them were alone. After engaging the teenage girl in conversation, the suspect allegedly put his hands under the victim’s clothes and touched her breasts.

Investigators said he also allegedly took one of her hands and placed it on his groin over his clothing. The suspect eventually told the victim to leave his classroom, which she did.

Detectives began investigating the case immediately. The suspect continued corresponding with the victim via social media and arranged to meet her at Palo Alto High School on the evening of Wednesday, June 15. Detectives were there to meet him instead and took him into custody without incident.

Farrell is a full-time employee of the Palo Alto Unified School District. He is not teaching any summer session classes.

Detectives are not aware of any additional victims at this time. Anyone who believes that their child may be a victim is welcome to call our 24-hour dispatch center at 650-329-2413.

Anyone with information about this incident is asked to call our 24-hour dispatch center at 650-329-2413. Anonymous tips can be e-mailed to or sent via text message or voice mail to 650-383-8984. Tips can also be submitted anonymously through our free mobile app, downloadable at or