Page 99 - CFDI Guide

ASPHYXIA INVESTIGATIONS

Asphyxia deaths are a lack of oxygen resulting in death. Generally, this is preceded by unconsciousness

then death if the oxygen flow continues to be obstructed. The obstructed flow may be mechanical, such as
by compression or blockage of the trachea (i.e. manual strangulation or choking), preventing inspiration

through normal breathing; or, other mechanical compression restricting blood flow to/from the brain
(arterial and venous) and oxygen delivery; or, medical event such as asthma or chronic obstructive

pulmonary disease (COPD); or, other mechanical such as preventing the chest from inhaling or exhaling –
preventing the lungs and/or diaphragm from doing their part; or, a chemical suppression of oxygen such as

carbon monoxide poisoning; or, other event such as drowning; or, positional asphyxia most commonly
seen in intoxicated deaths in which a person passes out in such a position their airway or blood flow is

blocked. The actions are numerous which can result in death – Accident, Suicide, and Homicide – Natural

(asthma, COPD – not listed as ‘asphyxia’). These may take place in any environment and condition, and
alone or with others, and include misadventures – such as a chokehold or sexual act, alone or with a
partner, gone awry.

Most common to criminal defense investigation are manual choking from the front, chokeholds or
ligatures from the back, or by hanging – suspended and unsuspended. So long as a person can or has their

airway or blood flow blocked, they can lose consciousness, and if this interruption continues can become
fatal. Non-fatal events may lead to brain damage, from surviving drowning to suffocation. In asphyxia

deaths, the full circumstances prior to and after the event are very important.

The evidence to look for is long – from vomit possibly indicating intoxication (confirmed by toxicology), to
being trapped and unable to breath – motor vehicle collision, caught in a ligature – clothing caught on

something, exposure to chemical – carbon monoxide, medical – anaphylaxis shock – an acute allergy,
which may cause respiratory failure. The question is – what circumstances resulted in the decedent, or

injured person, to suffer asphyxiation? Was it a sexual act gone bad – alone or with another person? Was
the scene cleaned by other persons, especially family who felt embarrassed? Are there scene indications

of a struggle? Is the ligature formed with a ‘safety’ to be able to release a knot? Does the victim have any
indications of self-defense, mutual combat, or other injuries?

The role of the CFDI in all such investigations becomes as vital as their demonstrated skill and knowledge.

The evidence is as much by exclusion as inclusion and additional information to be determined. The
incident scene and body (a separate scene) investigation will be the primary points of evidence.

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