A California Highway Patrol auto technician was taken into custody on December 3 after a month-long investigation uncovered a scheme to steal and sell vehicle components.
Arrest and Immediate Aftermath
The CHP announced that Dareth “John” Chau, a 54-year-old technician from Altadena, was arrested following an “extensive investigation into an alleged embezzlement scheme.” The arrest came as detectives completed a series of search warrants and seized evidence tied to the alleged theft.
Who Is Dareth “John” Chau?
Chau has worked for the CHP as an auto technician for several years, handling maintenance and repair tasks for the agency’s fleet. His long tenure and access to vehicle parts made him a key figure in the investigation.
The Co-Conspirator Connection
Investigators say Chau sold the stolen components to Mario Roberto Castellano, a resident of Castaic. Castellano, who was not an employee of the CHP, allegedly resold the parts or used them in vehicles he then sold to other customers.
How the Investigation Unfolded
Detectives began probing after noticing irregularities in the inventory of vehicle parts. The investigation expanded to a broader look at possible embezzlement by CHP personnel. Over several weeks, detectives collected evidence from both men’s homes.

Search Warrants and Evidence Recovery
After executing search warrants at Chau’s and Castellano’s residences, CHP investigators recovered:
- Stolen vehicle components that matched the parts missing from the agency’s inventory.
- Documentation indicating the sale of these parts to Castellano.
- Additional items linked to the alleged scheme.
Discovery of an Illegal Firearm
During the searches, authorities also found an illegal firearm. The weapon was seized as part of the evidence collection and will be examined in the context of the charges against Chau.
Charges Facing Dareth “John” Chau
Chau is now facing several serious accusations:
- Embezzlement by a public officer
- Receiving stolen property
- Grand theft by an employee or agent
- Conspiracy
These charges carry significant penalties, including potential imprisonment and restitution orders.
CHP’s Statement on the Incident
The CHP released a statement confirming the arrest and outlining the agency’s commitment to maintaining the integrity of its operations. The statement emphasized that the agency is cooperating fully with law enforcement and will continue to investigate any internal wrongdoing.
Context and Impact
Vehicle parts embezzlement undermines the safety and reliability of the CHP’s fleet. The agency’s ability to respond to emergencies depends on a fully maintained and trustworthy inventory. This incident highlights the need for stringent oversight and internal controls.
Key Takeaways
- Dareth “John” Chau, a CHP auto technician, was arrested on December 3 for embezzling vehicle parts.
- He sold the stolen components to Mario Roberto Castellano, who used or resold them.
- Search warrants uncovered stolen parts, documentation of sales, and an illegal firearm.
- Chau faces multiple serious charges, including embezzlement and conspiracy.
Closing Thoughts
The arrest of a CHP technician for embezzlement is a stark reminder that internal controls must be vigilant. As the investigation continues, the agency and the public will watch closely to see how the case unfolds and what measures will be taken to prevent similar incidents in the future.

