Japan has one of the lowest autopsy rates in the world. That might just be an interesting side note about Japan except for what is being overlooked. The case of Chisako Kakehi, who was arrested on suspicion of murdering eight lovers, six of whom had no autopsy performed, has brought attention to the situation once again. Nationwide, only 11.7 percent of "unusual deaths" resulted in autopsies, according to National Police Agency figures for 2014.

While there is no evidence that large numbers of crimes are being overlooked, the concern is that there might be. Other countries perform autopsies with much higher frequency. Japan's extremely low rate is far below England and Wales with 40 percent of unusual deaths investigated by autopsy, while in Sweden, 95 percent of unclear deaths have postmortem investigations carried out by forensic specialists.

In many cases, the barrier is respect for the deceased and consideration of the family's wishes. That is important, but in any unusual or unclear death, there is a chance that crimes are being overlooked. Toxicological analysis must also be conducted. Even when the cause of death appears obvious, it's best to be sure.