A majority of law enforcement agencies in Placer County now approach each overdose as a potential criminal scene, Craven said. Firefighters, whose first responsibility is to provide life-saving care, may handle the incident as a criminal investigation, tracking evidence or documenting witness’ statements. The coroner’s office has to perform increased testing on victims. Hospitals may have to turn over additional evidence, while ensuring its preservation, according to the Placer County Sheriff’s Office.