During the Meiji and Taisho eras, a high mortality rate existed in the Kanto district. However, in 1955 this began to decrease, leaving the western prefectures with a still higher rate of murder. This rate was especially high in the Osaka, Chugoku, and Shikoku districts. The incidence of infanticide occupies approximately 10 percent of the total cases of murder, but this does not coincide with the distribution of total murder incidents. The postwar rate of murder is 4 times higher than during the prewar period. The prewar mortality rate, however, was reduced to one-half during the war. Prewar male murder occurrences were only 90 percent of female murder incidents. The male murder incidents are 1.7 times as much as those of females after the war. The murder rate of young males in their 20's increased greatly after the war. Observations are made on the influence of season, occupation, age, and sex on the method of murder, quality of injury, etc. Maps, graphs, tables, and references are provided. (Author abstract modified)