Christopher John Ontiveros, who taught at Oxford Academy, was arrested in 2009. The 44-year-old Huntington Beach resident was accused of molesting a 17-year-old student he met at the school and sending sexually suggestive text messages to her.
A jury acquitted him of three felony counts and one misdemeanor charge. A misdemeanor count of touching an intimate part of another person was dismissed by prosecutors before trial.
Ontiveros' attorney David Cohn said a central focus of the trial were text messages on the girl's phone.
Ontiveros denied ever sending the girl any text messages, Cohn said.
"She and the principal testified that when (the girl) turned over the phone to the principal, (the accuser) took the time to delete every single message in her in box, which was kind of strange," Cohn said.
"My theory is that she sent the text messages," Cohn said, adding, "No one has ever seen a message in her outbox, only ones in the inbox ... And there's nothing in his phone that matched up."
One juror told defense attorneys after the verdicts, "One of the biggest things was the prosecution spent so much time on the text messages and photos, but they did nothing to support her credibility because she had lied to so many people," Cohn said.
It is not yet known if Ontiveros will try to return to a career in teaching.
City News Service contributed to this story.