Prior to 1945, Japanese governments attempted to identify criminals and isolate them from society and to help citizens organize themselves against crime. The police had a near monopoly on the powers of investigation, arrest, interrogation, adjudication, and execution; they used torture and organized public executions of criminals to warn the citizenry against becoming offenders. The citizens aided in crime prevention by organizing themselves into associations, such as the junin-gumi groups (10-family associations) which were collectively liable to the government for any crimes or disorders caused by members. Members who committed crimes were ostracized and left to join bands of criminals. The police were able to maintain some control over these bands through a system of informants. After World War II, the police were required to sever such traditional ties to criminal bands and to attempt to eliminate them. In addition, the new constitution called for a limitation on police methods through procedures of due process of law. Also, the police role became more difficult as the traditionally closely knit social units of the families, companies, communities, and schools began to weaken. Juvenile delinquency increased, and the number of female offenders rose as women were gradually liberated from their traditional roles. Only the companies still maintain some control over their members' misconduct: government and large-firm employees seldom become offenders. While the police were able to solve more than 80 percent of the crimes before 1945, the clearance rate has declined to between 56 and 58 percent in the 1970's. The decline is due primarily to an increase in thefts, and only 51 percent of these were solved. In the future, the police hope to control crime by working with the various social units in prevention efforts.