Complex sentence: His mother suffered 29 stab wounds and died most probably after several minutes due to a stab wound into the neck; one of the stab wounds however hit her brain thus probably instantly incapacitating her.
Split into simpler sentences: His mother suffered 29 stab wounds and died, most probably after several minutes, due to a stab wound to the neck. One stab wound hit her brain thus probably instantly incapacitating her.