This paper presents a case of double murder in which different mechanisms of suffocation, involving smothering, burking, and manual strangulation, were used. The victims are usually elderly people with disabilities and social isolation. The cases described here involve two women who were disabled and were murdered through blockage of the airway. Even though similar suffocating mechanisms were used in the murders, the autopsy findings differed between the two cases. This difference between the two can be explained by a preexisting medical condition that the younger victim had, which was quadriplegia resulting from cerebral hemorrhage, which limited herself-defense ability.