The identification of novel psychoactive substances (NPSs) in casework at the Los Angeles County Department of Medical Examiner (LACDME) is constantly evolving. The case detailed herein marks the first detection of metonitazene (MTZ) in forensic casework at the LACDME, which occurred in August 2023. Furthermore, bromazolam was found in the decedent's system and both substances were identified in drug evidence collected at the death scene. No other drugs were detected and the manner and cause of death were determined as accidental due to effects of bromazolam and MTZ. The concentrations detected were 1.6 ng/mL and 4.4 ng/mL of MTZ in the jugular blood and femoral blood, respectively, and 93 ng/mL of bromazolam in the femoral blood. Constraints in screening techniques conducted by toxicology laboratories create challenges in which numerous NPSs available on the illicit drug market can go undetected. Even if labs detect an NPS in their screening methodology, confirmation methods might not cover every NPS, given the impracticality of labs keeping pace with validations as new NPSs emerge in casework. The significance of testing medical evidence collected at death scenes by drug chemistry analysis becomes crucial when initial toxicology results are negative. In cases where there is evidence of potential drug paraphernalia, this is especially true as it can be pivotal in determining the cause and manner of death.