Homicide and robbery, which are heinous offenses, are regarded as offenses of which the number of non-reported cases is the smallest. In particular, the number of robbery cases has been rising sharply and qualitative changes have also been seen in recent years. In this special article, we have made analysis from various perspectives with the aim of identifying the actual conditions and background factors of these heinous offenses as clearly as possible, thereby contributing to taking more effective measures for the prevention of crime and the treatment of offenders. The occurrence of individual heinous offenses largely depends on individual circumstances concerned. Nevertheless, when overviewed and analyzed as a whole, such individual offenses are not unrelated to background factors of the society and the times but these factors are clearly reflected in individual offenses in diverse ways. Based on the results of the analyses shown above, we will point out particularly notable characteristics of heinous offenses with changing nature and background factors thereof, and indicate countermeasures and challenges.