The number of street robbery cases committed by juveniles has been increasing significantly in recent years. Most cases are committed with simplistic motives such as obtaining entertainment expenses, and they are committed by multiple perpetrators or perpetrators in groups in the nighttime, particularly late at night. Furthermore, not a few juveniles participate in the commitment of the offense while worrying about what accomplices would think of them rather than with the intention of taking money or articles, and they tend to become more violent as they commit the offense due to the group mind or mutual supervision. One of the reasons for the increase in street robbery cases is the fact that, due to the increase in overnight stores and restaurants including convenience stores, people go out late at night more frequently and therefore become targets for robbery by juvenile delinquents who are hanging around late at night. However, the increase in street robbery cases may be due to the combination of this reason and other background factors that are specifically seen in juvenile offenses. One of the background factors that are commonly seen in juvenile offenses in general is the decline in the guiding ability of parents and families. Although the majority of juvenile offenders have both parents, more than half of them have serious family problems such as conflict with family, isolation from family, or lack of emotional interaction with family. On the other hand, parents let their children alone, obey their children, or guide their children inconsistently, and the guiding ability to prevent juveniles from committing offenses has lost or declined in families of most juvenile robbery offenders. Another problem is that a number of juveniles do not go to school or go but fail to adapt themselves to school and not a few of them leave or drop out of school. Due to high unemployment rate among juveniles because of recessions, difficulties in finding jobs not only among high school dropouts but also among junior high school/high school graduates, and the decline in motivation for working among juveniles, the number of unemployed juveniles has been increasing. Juveniles tend to worry about what their friends think of them while lacking a sense of belonging to society or sympathy for the weak, and show tendency of justifying violence or irresponsible or apathetic attitude toward society. Such changes in the attitudes of juveniles should not be disregarded.
  These results imply the existence of a mechanism in which juveniles, who have left families or schools and found no place in society, suffer desolation of mind, and while hanging around late at night, they commit robbery for the purpose of obtaining money or articles quickly, without any sense of guilt but merely under the influence of friends, and finally damage victims by their violent acts.
  As such an increasing trend of street robbery cases committed by juveniles has been extending to adults, the increasing trend of street robbery cases committed by adults has also been intensified recently. There is a fear that, without taking prompt countermeasures against street robbery, which is easily imitated, it would be impossible to prevent not only the increase in street robbery cases by juveniles but also the intensification of the increasing trend of street robbery cases by adults.