[Forensic Life] Reasons Why Autopsy Is Necessary for Carbon Monoxide Poisoning Deaths

#1. He was a general’s personal guard. He was very diligent and intelligent, and the general trusted him as a reliable subordinate. One cold winter day, he was found dead naked in the bathroom of the general’s official residence. The unit was thrown into chaos, and the military police began an investigation and requested an autopsy. Upon arriving at the scene on the day of death and seeing the body, they were immediately able to estimate the cause of death.

After a person dies and the heart stops, blood settles downward due to gravity. The blood that settles in the blood vessels and appears as a dark red color on the corpse is called “livor mortis.” However, this soldier’s livor mortis was pink. It was the color of carboxyhemoglobin, which forms when carbon monoxide, which binds to hemoglobin 200 to 300 times more readily than oxygen, combines with hemoglobin. Before conducting the autopsy, they immediately rushed to the official residence, the scene of the incident. The shower facility inside the residence was equipped with an instant water heater. They immediately requested the military police to seal off the scene and advised contacting the Safety Management Corporation to check for carbon monoxide. Sure enough, carbon monoxide was leaking from the area with the boiler and instant water heater. High concentrations of carbon monoxide-hemoglobin were also confirmed in the blood. No other substances were detected, and there were no signs of injury, so the cause of death was determined to be carbon monoxide poisoning.

#2. New town apartment construction office. Office. The man running this office handed a refreshing soft drink to his junior, who was five years younger and from the same hometown. The junior gulped down the drink in one go. Shortly after, the junior kept mumbling that he was sleepy and then fell asleep. He and a colleague took the junior to the shower room. The shower room window was sealed shut. He stripped the junior naked, released the gas safety lock on the water heater, turned on the water, and closed the door. The junior died shortly after. After some time, they entered holding their noses and mouths, held their breath, opened the window, thoroughly removed the sealed window frame, locked the gas safety lock, and called 119, urgently requesting help saying, “It seems someone has died.”

The police confirmed the body at the scene and consulted the medical examiner, who concluded death by carbon monoxide poisoning, and treated it as a simple accidental death. However, it was suspicious that the gas water heater was a new model, not an old one prone to carbon monoxide leaks. The police changed their plan from not performing an autopsy to conducting one. The cause of death was indeed carbon monoxide poisoning, but zolpidem, a sleeping pill, was detected in the blood. The amount was enough to cause sleep. It did not make sense that a sleeping person would die while showering with hot water. When the police investigated the deceased junior’s insurance, they found that the person who reported the accident was the beneficiary of about 1.5 billion won in death insurance. They also discovered that he had recently been prescribed and purchased sleeping pills and that the instant water heater had been installed recently. The perpetrators were charged with murder and found guilty.

Carbon monoxide is a colorless, odorless gas that is lighter than air but extremely toxic, capable of killing a person at concentrations of about 0.1% in the air. Situations where incomplete combustion gases can occur in confined spaces must always be approached with caution and care. Also, when death is judged to be caused by carbon monoxide poisoning, it is important to remember that other factors or the possibility of homicide may always be involved, so postmortem examination, i.e., autopsy, may be necessary.

Yoo Seong-ho, Forensic Scientist