Familial Suicidal Pact in an Enclosed Room-A Case Report

Abstract

Background: Determining the cause and manner of death in cases where fire injuries have been alleged has major medicolegal implications. In enclosed-space fires, lethal mechanisms typically include inhalation of hot, oxygen-depleted smoke with carbon monoxide (CO) toxicity. Here, cutaneous burns can be lethal but in most cases are predominantly post-mortem, as the suffocation that precedes these is invariably fatal in itself.
Case series: Four related decedents were found in a single-room dwelling. The room was bolted from inside. There were allegations of familicide. However, a suicide pact note was recovered later. Also, there were no signs of forced entry or struggle. All four showed soot within the airways, congested/edematous laryngo-tracheal mucosa, heavy edematous lungs with fine froth, and cherry-pink hypostasis. COHb levels were 44% (adult male), 41% (adult female), 32% (child 1), and 29% (child 2). Externally, burns involved mixed depths (adults ~60–70% TBSA; children ~35–45%) but lacked vital inflammatory margins; several blisters had clear fluid, supporting post-mortem burning. Careful layered neck dissection in all four revealed no strap-muscle hemorrhage, no carotid sheath bleeding, and intact hyoid/laryngeal cartilages; no ligature marks or defensive injuries were present.
Discussion: Crime Scene, autopsy and toxicology correlation supports asphyxial deaths from hot, oxygen-poor smoke with contributory CO toxicity, followed by post-mortem cutaneous burning. The locked scene, suicide note, uniform inhalational findings, and absence of neck trauma favour a suicide pact over familicide or dyadic (homicide–suicide) death.
Conclusion: In enclosed-room family fatalities, airway soot plus elevated COHb are the most persuasive indicators of life during the fire. Absence of vitality timestamps burn injuries to the post-mortem interval. Clear, physiologically accurate certification of the cause of death “asphyxia due to inhalation of hot, oxygen-depleted smoke with contributory CO toxicity” helps prevent misclassification and guides appropriate medicolegal decisions.