Pesticide-related fatalities referred for diagnostic difficulty: a forensic case series highlighting scene-toxicology discordance.

Fatal pesticide poisonings pose a persistent medico-legal challenge, particularly when post-mortem toxicological confirmation is inconclusive despite strong circumstantial and clinical evidence. This study aimed to examine forensic decision-making, evidentiary discordance, and toxicological limitations in pesticide-related deaths referred for diagnostic difficulties to the First Forensic Medicine Specialization Board (FFMSB) in Türkiye. A retrospective descriptive forensic case series was examined which included pesticide-related deaths evaluated by the FFSMB of the Council of Forensic Medicine, Türkiye, between 2013 and 2022. Case files were reviewed for sociodemographic data, scene investigation findings, clinical course, autopsy and histopathology results, and post-mortem toxicological analyses across multiple biological matrices. The findings were summarized descriptively with emphasis on the route of pesticide identification and reasons for toxicological non-detection. Fifty-one fatal cases were included. A pesticide product was identified at the death scene in 56.9% of the cases, whereas toxicological analyses confirmed pesticide exposure in 31.4% of the cases. Aluminium phosphide and methomyl were the most frequently detected agents. Toxicological positivity varied by biological matrix, with the highest detection rate in the gastric content, followed by blood and urine. Discordance between circumstantial evidence and toxicological findings was most often associated with agent volatility, rapid metabolism, delayed sampling, prior medical interventions, and limited availability of appropriate matrices. Post-mortem toxicology alone was often insufficient to support medicolegal certification in fatal pesticide poisonings. Accurate determination of cause of death depended on the integrated assessment of scene findings, clinical information, autopsy results, and multimatrix toxicological analyses. These findings highlight the need for standardized scene documentation and systematic forensic evaluation in cases of suspected pesticide-related death.