Within the criminal justice system of Japan, there exist three basic features that characterize its operations. First, the institutions—police, government prosecutors' offices, courts, and correctional organs—maintain close and cooperative relations with each other, consulting frequently on how best to accomplish the shared goals of limiting and controlling crime. Second, citizens are encouraged to assist in maintaining public order, and they participate extensively in crime prevention campaigns, apprehension of suspects, and offender rehabilitation programs. Finally, officials who administer criminal justice are allowed considerable discretion in dealing with offenders.
In 2021, the Japanese police recorded 568,104 crimes, of which 8,821 were cases of murder, robbery, arson, rape, sexual assault, indecent assault, kidnapping, and human trafficking, which are designated as major crimes (jūyō hanzai, 重要犯罪) by the National Police Agency. The arrest rate, which indicates the percentage of unsolved crimes recognized by the Japanese police by 2021 for which the perpetrators were arrested in 2021, was 46.6%. Of these, the arrest rate for cases involving murder, robbery, arson, rape, sexual assault, indecent assault, kidnapping, and human trafficking, which are designated as major crimes, was 93.4%.
As of 2001, Japan had a conviction rate of over 99.8%, even higher than contemporary authoritarian regimes. Scholars say the biggest reason for Japan's very high conviction rate is the country's low prosecution rate and the way Japan calculates its conviction rate is different from other countries. According to them, Japanese prosecutors only pursue cases that are likely to result in convictions, and not many others. According to Professor Ryo Ogiso of Chuo University, prosecutors defer prosecution in 60% of the cases they receive, and conclude the remaining 30% or so of cases in summary trials. This summary trial is a trial procedure in which cases involving a fine of 1,000,000 yen or less are examined on the basis of documents submitted by the public prosecutor without a formal trial if there is no objection from the suspect. Only about 8% of cases are actually prosecuted, and this low prosecution rate is the reason for Japan's high conviction rate. According to Keiichi Muraoka, a professor at Hakuoh University, the 60% suspension of prosecution in Japan is due to excessive fear that prosecutors will lose the case and ruin their reputation.
After the lay judge system ( system, ) in which citizens participate, began in 2009, the prosecution and conviction rates have declined; in 2006, the prosecution rate for murder, including attempted murder, was 56.8%; as of 2017, the rate had dropped to 28.2%. The overall conviction rate in the first instance also dropped to 97.8% as of 2017. Although the Ministry of Justice noted that the decline in the prosecution rate began before the introduction of the lay judge system, some lawyers and scholars have pointed out that the introduction of the lay judge system, in which citizens participate, has led to greater emphasis on direct evidence and testimony at trial and more cautious judgment on inferences. For example, according to Akira Sugeno, a lawyer who is a senior member of the Japan Federation of Bar Associations, a 2016 street crime in which three people were attacked with kitchen knives was charged with injury because there was no evidence of intent to kill, but before the system change it would have been charged as attempted murder because the judge's reasoning would likely have found intent to kill. They also pointed out that the reformed system has reduced lengthy interrogations and other forms of aggressive evidence-gathering, making it more difficult to create false convictions.
History 1868–1947 Until the Meiji Restoration in 1868, the criminal justice system in Edo Japan was controlled mainly by daimyōs. Public officials, not laws, guided and constrained people to conform to moral norms. In accordance with the Confucian ideal, officials were to serve as models of behavior; the people, who lacked rights and had only obligations, were expected to obey. Such laws as did exist were transmitted through local military officials in the form of local domain laws. Specific enforcement varied from domain to domain, and no formal penal codes existed. Justice was generally harsh, and severity depended upon one's status. Kin and neighbors could share blame for an offender's guilt: whole families and villages could be flogged or put to death for one member's transgression.
After 1868, the justice system underwent rapid transformation. The first publicly promulgated legal codes, the Penal Code of 1880 and the Code of Criminal Instruction of 1880, were based on French models, i.e., the Napoleonic Code. Offenses were specified, and set punishments were established for particular crimes. Both codes were innovative in that they treated all citizens as equals, provided for centralized administration of criminal justice, and prohibited punishment by ex post facto law. Guilt was held to be personal; collective guilt and guilt by association were abolished. Offenses against the emperor were spelled out for the first time.
Innovative aspects of the codes notwithstanding, certain provisions reflected traditional attitudes toward authority. The prosecutor represented the state and sat with the judge on a raised platform—his position above the defendant and the defense counsel suggesting their relative status. Under a semi-inquisitorial system, primary responsibility for questioning witnesses lay with the judge, and defense counsel could question witnesses only through the judge. Cases were referred to trial only after a judge presided over a preliminary fact-finding investigation in which the suspect was not permitted to have counsel. Because in all trials, available evidence had already convinced the court in a preliminary procedure, the defendant's legal presumption of innocence at trial was undermined, and the legal recourse open to his counsel was further weakened.
The Penal Code was substantially revised in 1907 to reflect the growing influence of German law in Japan, and the French practice of classifying offenses into three types was eliminated. More importantly, where the old code had allowed very limited judicial discretion, the new one permitted the judge to apply a wide range of subjective factors in sentencing.
Since 1947 After World War II, occupation authorities initiated reform of the constitution and laws in general. Except for omitting offenses relating to war, the imperial family, and adultery, the 1947 Penal Code remained virtually identical to the 1907 version. The criminal procedure code, however, was substantially revised to incorporate rules guaranteeing the rights of the accused. The system became almost completely accusatorial, and the judge, although still able to question witnesses, decided a case on the evidence presented by both sides. The preliminary investigative procedure was suppressed. The prosecutor and defense counsel sat on equal levels, below the judge. The laws on indemnification of the wrongly accused and laws concerning juveniles, prisons, probation, and minor offenses were also passed in the postwar years to supplement criminal justice administration.
In 2020, Japan ranked 9th in the sub-ranking "criminal justice" in the World Justice Project's Rule of Law Index, second highest among G7 countries. The World Prison Brief had the country incarceration rate in 2021 at 37 per 100,000 people, second lowest in the OECD and a reduction of 42% compared to 2006.
Criminal investigation In the Empire of Japan, the criminal investigation was presided over by prosecutors, like the Ministère public does in French law. Then, with the 1947 Police Law and 1948 Code of Criminal Procedure, the responsibility of investigations has been defined as uniquely resting with police officers. In order to fulfill this responsibility, criminal investigation departments were set up in each prefectural police department. After the establishment of the 1954 amended Police Law, these departments are supervised by the Criminal Affairs Bureau of the National Police Agency.
Criminal procedure The nation's criminal justice officials follow specified legal procedures in dealing with offenders. Once a suspect is arrested by police officers, the case is turned over to attorneys in the Supreme Public Prosecutors Office, who are the government's sole agents in prosecuting lawbreakers. Under the Ministry of Justice's administration, these officials work under Supreme Court rules and are career civil servants who can be removed from office only for incompetence or impropriety. Prosecutors presented the government's case before judges in the Supreme Court and the four types of lower courts: high courts, district courts, summary courts, and family courts. Penal and probation officials administer programs for convicted offenders under the direction of public prosecutors (see Judicial system of Japan).
After identifying a suspect, police have the authority to exercise some discretion in determining the next step. If in cases pertaining to theft, the amount is small or already returned, the offense petty, the victim unwilling to press charges, the act accidental, or the likelihood of repetition not great, the police can either drop the case or turn it over to a prosecutor. Reflecting the belief that appropriate remedies are sometimes best found outside the formal criminal justice mechanisms, in 1990, over 70 percent of criminal cases were not sent to the prosecutor.
Juveniles Police also exercise wide discretion in matters concerning juveniles. Police are instructed by law to identify and counsel minors who appear likely to commit crimes, and they can refer juvenile offenders and non-offenders alike to child guidance centers to be treated on an outpatient basis. Police can also assign juveniles or those considered to be harming the welfare of juveniles to special family courts. These courts were established in 1949 in the belief that the adjustment of a family's situation is sometimes required to protect children and prevent juvenile delinquency. Family courts are run in closed sessions, try juvenile offenders under special laws, and operate extensive probationary guidance programs. The cases of young people between the ages of fourteen and twenty can, at the judgment of police, be sent to the public prosecutor for possible trial as adults before a judge under the general criminal law.
Citizens
Arrest Police have to secure warrants to search for or seize evidence. A warrant is also necessary for an arrest, although if the crime is very serious or if the perpetrator is likely to flee, it can be obtained immediately after arrest. Within forty-eight hours after placing a suspect under detention, the police have to present their case before a prosecutor, who is then required to apprise the accused of the charges and of the right to counsel. Within another twenty-four hours, the prosecutor has to go before a judge and present a case to obtain a detention order. Suspects can be held for ten days (extensions are granted in most cases when requested), pending an investigation and a decision whether or not to prosecute. In the 1980s, some suspects were reported to have been mistreated during this detention to exact a confession. These detentions often occur at cells within police stations, called . A suspect can be taken into custody after arrest and before prosecution for up to 23 days.
Prosecution