A La Costa Canyon High School and former MiraCosta College math teacher was arrested Wednesday morning on suspicion of possession of child sexual abuse material, California Attorney General Rob Bonta announced.
Joseph Anthony Zyburt, 55, is facing three felony charges, including possession of child pornography on a computer, possession on a cellphone and attempted purchase of child pornography, according to a criminal complaint and jail records.
San Dieguito Union High School District officials said Zyburt was placed on administrative leave near the start of the school year after the district learned he was under criminal investigation. The district said in a statement that it learned of his arrest on Wednesday.
“In early September 2025, district officials were notified that law enforcement was opening an investigation into a matter involving Joseph Zyburt,” the district said in its statement. “While the district was not provided with any specifics at the time, Mr. Zyburt was immediately removed from the classroom and placed on administrative leave.”
District officials said they had no other information about Zyburt’s arrest beyond what Bonta’s office provided.
“This news is deeply disturbing and the District hopes justice will be served,” it said in the statement.
Bonta said investigators identified Zyburt as someone who was allegedly attempting to purchase child sexual abuse material on the internet, and a subsequent investigation revealed that he allegedly already possessed such images on at least two electronic devices.
“When someone who is entrusted with the care of our youth is revealed to be harboring child sexual abuse material, it is not only a crime, but also a betrayal of trust,” Bonta said in a statement.
Records from Transparent California show Zyburt has taught at Carlsbad’s La Costa Canyon High since at least 2013.
Zyburt was also a part-time faculty member in the math department at MiraCosta College, a community college in Oceanside, dating back to 2001, according to MiraCosta spokesperson Kristen Gonzales.
“Mr. Zyburt taught dual enrollment math classes under an agreement with the high school district,” Gonzales said, adding that he last taught at the school during the summer 2025 semester.
A MiraCosta class schedule showed Zyburt was supposed to teach two additional math courses in fall 2025. Gonzales confirmed that he began teaching those courses last August, but “was replaced soon after.” It’s believed he left that position around the same time the high school district placed him on administrative leave.
Bonta said the investigation of Zyburt was conducted by a white-collar investigations team from the California Department of Justice, with help from the Carlsbad Police Department and an FBI computer forensics team. Deputy attorney generals from Bonta’s office will be prosecuting the case.
“We appreciate the outstanding work and professionalism of the Department of Justice, whose thorough investigation was instrumental in this arrest,” Carlsbad Police Chief Christie Calderwood said in a statement. “This case highlights the importance of strong interagency partnerships in keeping our communities safe.”
According to a criminal complaint provided by Bonta’s office, Zyburt allegedly attempted to purchase child sexual abuse material sometime between October 2024 and January 2025. Later in 2025, he is alleged to have possessed such images on both a desktop computer and cellphone.
Sheriff’s Office jail records showed Zyburt was booked Wednesday morning into the Vista Detention Facility on three felony charges and he’s expected to be arraigned Friday in Vista Superior Court.