Allende caused an accident while he was driving under the influence, causing emergency response by the California Highway Patrol (CHP) to the scene. The CHP then billed Allende $360 for costs, including vehicle storage, “in custody” activities, and traffic control. Allende and others filed a class action complaint against the CHP, arguing that they should have been billed only for services at the scene of the incident or for officers going to and from the scene. The trial court granted his motion for summary judgment. The CHP then filed a petition for writ of mandate, which was granted by the appellate court. Government Code section 53156(a) authorizes the recovery of reasonable costs “directly arising” from the emergency response. Here, the trial court narrowly interpreted “directly arising” to mean only those costs based upon the incident itself. The CHP was entitled to reimbursement of costs for police services associated with removing vehicles, investing the cause of the accident, conducting field sobriety tests, etc. However, costs such as testifying against a DUI defendant arise from the decision to prosecute, and are not recoverable.