Forensic challenges in a case of suspected filicide, matricide, and post-mortem dismemberment.

Familicide represents one of the most complex forms of domestic violence in forensic practice. Among intrafamilial homicides, filicide and matricide pose major medico-legal and criminological challenges, particularly when autopsy findings are nonspecific or severely altered by post-mortem changes. We report an unusual forensic case involving the deaths of a 3-year-old child and his grandmother, both initially characterized by uncertain manners of death. The child was found dead by his mother while sleeping in a shared bed with multiple pillows. Autopsy examination revealed facial injuries and histological findings consistent with mechanical asphyxia, including diffuse alveolar hemorrhage, pulmonary emphysema, and rupture of the alveolar septa. Toxicological analyses were negative. Genetic investigations identified variants of uncertain significance associated with cardiomyopathies; however, parental testing demonstrated inherited variants, making a genetic arrhythmic cause unlikely. Circumstantial inconsistencies and internet searches performed by the mother regarding suffocation methods further supported homicidal smothering. Epidemiological evidence indicating that accidental sleep-related suffocation occurs predominantly during infancy made the child's age atypical for an accidental mechanism. Five months later, the dismembered and partially skeletonized body of the child's grandmother was discovered inside the family home. Autopsy and histological findings suggested death due to neck compression, although advanced putrefaction and extensive post-mortem dismemberment prevented definitive differentiation between suicidal hanging and homicidal strangulation. This case highlights the critical importance of integrating autopsy, histological, toxicological, genetic, and investigative findings in complex intrafamilial deaths, particularly when traumatic signs are limited or post-mortem destruction compromises forensic interpretation.