Press release from the Humboldt County Sheriff’s Office:

In May 2023, the Humboldt County Sheriff’s Office began an investigation into an individual suspected of possessing child pornography. During this investigation, the suspect was identified as Matthias Alexander Wilberger of Eureka. On June 30, 2023, Matthias was arrested for PC 311.11(a) – Possession of Child Pornography. During a subsequent interview, Matthias admitted to possessing the discovered material.

Following his arrest, investigators obtained a search warrant to conduct a forensic download of his cellphone. The examination revealed a large quantity of additional images and videos of child pornography. While any child pornography is disturbing, the content discovered on Matthias’ phone was especially graphic and horrifying. Due to the amount and nature of the material, Matthias’ charges were amended to:

  • PC 311.11(c)(1) – Possession of Child Pornography more than 600 images
  • PC 311.11(c)(2) – Possession of Child Pornography involving sexual sadism and masochism 

On December 13, 2023, Matthias pled guilty to both charges. On January 26, 2024, he was sentenced to five years and eight months in state prison. However, the Judge suspended execution of the sentence, placing Matthias on probation. As part of his probation, Matthias was ordered to register as a sex offender, complete a sex offender treatment program, and serve 365 days in the Humboldt County Correctional Facility.

 

On July 12, 2024, after serving 168 actual days, Matthias was released from custody.

 

On May 22, 2025, during an unannounced sex offender registrant compliance check, a Sheriff’s detective contacted Matthias at his residence. During the compliance check, the detective examined Matthias’ cellphone and located material that violated the terms of his probation. Matthias was arrested and booked into the Humboldt County Correctional Facility for violation of probation.

 

On June 18, 2025, Matthias appeared in Humboldt County Superior Court, admitted to the probation violations, and pled guilty. On September 16, 2025, Superior Court Judge Neel imposed the original sentence of five years and eight months in state prison.

 

IMPORTANCE OF COMPLIANCE CHECKS:


The Humboldt County Sheriff’s Office routinely conducts sex offender registration compliance checks. These checks are a vital public safety function that ensure individuals required to register as sex offenders follow all statutory requirements. Compliance checks verify that registrants are residing at their reported addresses, maintaining current and accurate personal information, and adhering to restrictions imposed by law.

 

The successful completion of these compliance checks enhances public safety by:

  • Confirming accurate records in the sex offender registry
  • Identifying and addressing violations or non-compliance
  • Strengthening community trust through proactive monitoring
  • Deterring offenders from attempting to evade registration requirements

This case demonstrates the critical importance and effectiveness of these compliance checks conducted by law enforcement agencies throughout Humboldt County.

 

The Humboldt County Sheriff’s Office would like to also recognize the Humboldt County District Attorney’s Office for their dedication and hard work in prosecuting these difficult cases.