Prosecutor: Are you able to say whether or not Caleb died from a catastrophic asphyxiating event of unknown causes?
Pathologist: I believe that is likely. […]
Prosecutor: In relation to Laura […] her cause of death was consistent with smothering?
Prosecutor: Including deliberate smothering?
Prosecutor: And that she probably died from an acute catastrophic asphyxiating event of unknown causes?
Pathologist: Yes. – (Transcript pp. 746-48)
The above exchange occurred during the seven-week trial leading to Kathleen Folbigg’s conviction for the deaths of her four infant children (Caleb, Patrick, Sarah and Laura) between 1989 and 1999. During the trial, the word "asphyxia" in its various forms (-ate; -ation; -ating) was used 208 times; "smother" (-ing; -ed) 221 times; and "consistent with" 233 times.
The pathologists and doctors concurred that the absence of external injuries was "consistent with" Caleb dying of a "catastrophic asphyxiating event". This was repeated for each of the four children by each of the doctors, with strangling or smothering likely to be uppermost in the minds of the jurors.
Of course, Folbigg's wrongful conviction had numerous factors. We have no way of knowing why the jury decided as it did.
But there are good reasons for forensic medicine practitioners and advocates to rethink their understanding – and use – of these words.
The semantic journey of asphyxia.
"Asphyxia" first appeared in print in 1699 defined as "without any Pulse, or sign of Life". Predictably, this meaning "stoppage of pulse" then sprouted the meaning "stoppage of respiration" – a lack of breath is a salient sign of lifelessness.
Subsequently, the path has been rocky, and it is now understood variously by forensic doctors around the world. What is agreed, however, is that "asphyxia" is not a diagnosis; it is not a condition that can be pointed at or diagnosed.
As far as lay understandings go, things get murkier. Modern dictionaries list many senses but privilege "respiratory failure", with "suffocation" usually given as a synonym; this in turn is defined as the interruption of breathing, including some means by which it’s brought about (for example, smothering, throttling).