Homicidal violence including blunt force injury, sharp force injury, asphyxia, and gunshot wounds cannot be excluded.
1706, "stoppage of pulse," from Modern Latin, from Greek asphyxia "stopping of the pulse," from a- "not" (see a- (3)) + sphyzein "to throb." The current sense of "suffocation" is from 1778, but it is a "curious infelicity of etymology" [OED] because victims of suffocation have a pulse for some time after breathing has stopped.
asphyxia as·phyx·i·a (ās-fĭk'sē-ə)
A condition in which an extreme decrease in the amount of oxygen in the body accompanied by an increase of carbon dioxide leads to loss of consciousness or death.