Until the Meiji Restoration in 1868, the Japanese criminal justice system was controlled mainly by daimyo. 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. (see Criminal punishment in Edo-period Japan for details)
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 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 important, 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.
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 evidence presented by both sides. The preliminary investigative procedure was suppressed. The prosecutor and defense counsel sat on equal levels, below the judge. 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 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, responsibility of the investigation has been defined that uniquely located at police officers. In order to fulfill this responsibility, Criminal Investigation Departments were set up in each police organization. After the establishment of the 1954 amended Police Law, these departments are supervised by the Criminal Affairs Bureau of the National Police Agency.
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 a 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.
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.
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 almost all 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 daiyo kangoku.
Prosecution can be denied on the grounds of insufficient evidence or on the prosecutor's judgment. Under Article 248 of the Code of Criminal Procedure, after weighing the offender's age, character, and environment, the circumstances and gravity of the crime, and the accused's rehabilitative potential, public action does not have to be instituted, but can be denied or suspended and ultimately dropped after a probationary period. Because the investigation and disposition of a case can occur behind closed doors and the identity of an accused person who is not prosecuted is rarely made public, an offender can successfully reenter society and be rehabilitated under probationary status without the stigma of a criminal conviction.
Institutional safeguards check the prosecutors' discretionary powers not to prosecute. Lay committees are established in conjunction with branch courts to hold inquests on a prosecutor's decisions. These committees meet four times yearly and can order that a case be reinvestigated and prosecuted. Victims or interested parties can also appeal a decision not to prosecute.
Most offenses are tried first in district courts before one or three judges, depending on the severity of the case. Defendants are protected from self-incrimination, forced confession, and unrestricted admission of hearsay evidence. In addition, defendants have the right to counsel, public trial, and cross-examination. Trial by jury was authorized by the 1923 Jury Law but was suspended in 1943. A new lay judge law was enacted in 2004 and came into effect in May 2009, but it only applies to certain serious crimes.
The judge conducts the trial and is authorized to question witnesses, independently call for evidence, decide guilt, and pass sentence. The judge can also suspend any sentence or place a convicted party on probation. Should a judgment of not guilty be rendered, the accused is entitled to compensation by the state based on the number of days spent in detention.
Criminal cases from summary courts, family courts, and district courts can be appealed to the high courts by both the prosecution and the defense. Criminal appeal to the Supreme Court is limited to constitutional questions and a conflict of precedent between the Supreme Court and high courts.
The criminal code sets minimum and maximum sentences for offenses to allow for the varying circumstances of each crime and criminal. Penalties range from fines and short-term incarceration to compulsory labor and the death penalty. Heavier penalties are meted out to repeat offenders. Capital punishment consists of death by hanging and is usually imposed for multiple homicides.
After a sentence is finalized, the only recourse for a convict to gain an acquittal is through a retrial. A retrial can be granted if the convicted person or their legal representative show reasonable doubt about the finalized verdict, such as clear evidence that past testimony or expert opinions in the trial were false.
The first trial by citizen judge, “saiban-in”, began August 3, 2009 under a new law passed in 2004. Six citizens became lay judges and joined three professional judges to determine the verdict and sentence the defendant. Japan belongs to an inquisitory system of criminal process. Therefore, a judge oversees the proceedings and also determines the guilt and the sentence of the accused. The citizen lay judges as well as professional judges are allowed to put forth questions to defendants, witnesses and victims during the trial. The new system aims to invite participation of the wider community and also provide a speedier, more democratic justice system, according to Eisuke Sato, the justice minister. The first trial by lay judge lasted four days, while some comparable criminal cases may last years under the old system. The historic trial of 72-year-old Katsuyoshi Fujii who stabbed his 66-year-old neighbor to death had substantial media attention. The selected lay judges must be voters, at least 20 years old, and possess a secondary level education. Professional lawyers and politicians may not serve as lay judges in the new system. At least one judge must concur with the majority vote from the lay judges in regards to a guilty verdict, however a majority not guilty verdict by the lay judges will stand. During the inaugural case, the citizens relied on the professional judges to help ascertain a sentence for the verdict decided upon, but felt confident in their interpretation of the trial arguments presented by prosecution and defence.
One of the main features of the Japanese criminal justice system well known in the rest of the world is its extremely high conviction rate, which exceeds 99%. Some in the common law countries argue that this is to do with elimination of the jury system in 1943, however, trials by jury were rarely held as the accused had to give up the right to appeal. Lobbying by human rights groups and the Japan Federation of Bar Associations resulted in the passing of a judicial reform bill in May, 2004, which introduced a lay-judge system in 2009, which is often confused with jury system in common law countries.
J. Mark Ramseyer of Harvard Law School and Eric B. Rasmusen of Indiana University examine if the accusation is in fact warranted. In their paper ("Why Is the Japanese Conviction Rate So High?") they examined two possibilities. One is that judges who come under the control of central bureaucracy are pressured to pass a guilty verdict, ensuring high conviction. Another possibility is that, given that the non-jury system under inquisition system has predictable ruling on guilt, Japan's understaffed prosecutors working on low budgets only bring the most obviously guilty defendants to trial, and do not file indictments in cases in which they are not certain they can win.
All Japanese court rulings are accessible in digital format; the two academics examined every case after World War II in which the court found the defendant not guilty. The result is mixed. Simple statistical analysis shows that the judge's later career tends to be negatively affected by a non-guilty verdict. However, by examining the individual cases, the two academics found that all of those cases which negatively affected judges' careers had political implications (such as labour law or electoral law) and that the facts of the case (i.e. the defendants committing the accused deed) itself were never in dispute. However, judges delivered 'not guilty' verdicts on technicalities such as statutes of limitation or constitutional arguments, which were subsequently reversed in a higher court. In cases in which the judge delivered a 'not guilty' verdict because they ruled that there was insufficient evidence to ascertain that the defendants did the accused deed, the judge suffered no negative consequence. For this reason, the paper argued that Japanese judges are politically conservative in legal interpretation but are not biased in matter of fact.
In the matter relating to Japanese prosecutors being extremely cautious, the paper found ample evidence for it. In Japan, 99.7% of all the cases brought to court resulted in conviction, while in the U.S. the figure is 88%. According to a cited research, in the U.S. the accused contest guilt in 22% of federal cases and 11% of state cases, while in Japan, the ratio is modestly less. The paper attributes this difference to greater predictability of the outcome in Japanese cases. This is due to two reasons. One is that it is the judge rather than the jury who determines the verdict. As judges "have seen it all before" and the lawyers on both sides "have seen them seeing it", as they can read the judge's previous ruling (which includes written reasoning for the previous verdict), the way that the judge thinks and argues is very predictable.
Secondly, Japanese trials before the institution of the current lay judge system, were discontinuous. The defense and the prosecutor would first gather in front of the judges and present the issue. Then, the court would enter recess and both sides would go back to prepare their case. As they reconvened on different dates, they would then present each case which the judges examined, the court would be put in recess again and each side would go back to gather further evidence. Some complex trials took years or even a decade to conclude which is impossible under jury system. During the questioning of evidence, judges were explicit about their opinions by the way they questioned the evidence, which gave greater predictability about the final verdict.
For this reason, the prosecutor is far more likely to bring in the case where conviction is assured and the accused is far more likely to settle.
Moreover, the paper found that Japanese prosecutors have a far more pressing need to be selective. In the U.S., the federal government employs 27,985 lawyers and the states employ another 38,242 (of which 24,700 are state prosecutors). In Japan, with about a third of U.S. population, the entire government employs a mere 2,000. Despite Japan having a low crime rate, such numbers create a significant case overload for prosecutors. In the U.S., there are 480 arrests (96 serious cases) per year per state prosecutor. (The actual figure is lower as some are prosecuted in federal court). In Japan, the figure is 700 per year per prosecutor. In the U.S., a rough estimate is that 42% of arrests in felony cases result in prosecution - while in Japan, the figure is only 17.5%.
In murder, U.S. police arrested 19,000 people for 26,000 murders, in which 75% were prosecuted and courts convicted 12,000 people. In Japan, 1,800 people were arrested for 1,300 murders, but prosecutors tried only 43%. Had the allegation that Japanese prosecutors use weak evidence mostly based on (forced) confessions to achieve convictions been true, the larger proportion of arrests would have resulted in prosecutions and eventual conviction. But the opposite is true. In fact, the data indicates that Japanese prosecutors bring charges only when the evidence is overwhelming and likelihood of conviction is near absolute, which gives a greater incentive for the accused to confess and aim for a lighter sentence, which, in turn, results in a high rate for confession.
The Japanese criminal justice system, despite retaining the death penalty, is relatively lenient in sentencing by the standard of the United States. Outside capital cases, many of those sentenced to life sentences are paroled within 15 years. Those convicted of less heinous murder and manslaughter are likely to serve less than 10 years. Those convicted of rape will often serve less than two to five years. It is even possible for someone convicted of murder to serve a suspended sentence if the defense successfully argues for mitigating circumstances. Moreover, in Japanese criminal proceedings the conviction and sentencing phase are separate. In the Japanese criminal justice system, these are distinct phases, echoing that of common law jurisdictions where sentencing is usually remitted to a later hearing after a finding of guilt. The court proceedings first determine guilt, then a second proceeding takes place to determine the sentence. Prosecutors and defense teams argue each phase. Defense lawyers, given the predictability of the outcome in term of guilt once the charge is brought, together with leniency of punishment (except in death penalty cases), often advise the accused to confess their guilt in trial. Remorse is seen as a mitigating factor which tends to bring reduced sentences.
Many Western human rights organizations alleged that the high conviction rate is due to rampant use of conviction solely based on confession. Confessions are often obtained after long periods of questioning by police as those arrested may be held for up to 23 days. This can, at times, take weeks during which time the suspect is in detention and can be prevented from contacting a lawyer or family.
Article 38 of Japan's Constitution categorically requires that "no person shall be convicted or punished in cases where the only proof against suspect is his/her own confession," In practice, this constitutional requirement take a form of safeguard known as "revelation of secret" (Himitsu no Bakuro, lit "outing of secret"). Because suspects are put through continuous interrogation which could last up to 23 days as well as isolation from the outside world, including access to lawyers, both the Japanese judiciary and the public are well aware that confession of guilt can easily be forced. Consequently, the court (and the public) take the view that mere confession of guilt alone is never any sufficient ground for conviction.
Instead, for confession to be a valid evidence for conviction, the Japanese court requires confession to include revelation of verifiable factual matter which only the perpetrator of the crime could have known such as the location of an undiscovered body or the time and place the murder weapon was purchased, a fact about the crime scene, etc. Furthermore, to safeguard against the possibility that the interrogator implanting such knowledge into confession, the prosecutor must prove that such revelation of secret was unknown to the police until the point of confession. For example, in the Sachiura murder case which happened in 1948, the conviction was initially secured by the confession of the location of the body which was yet to be discovered. However, it later transpired that the police likely knew the location of the body and this created a possibility that the confession of the location of the body could be forged and implanted by the investigating police, resulting in the higher court declaring the confession unsafe and reversing the verdict.
While it is impossible for an innocent suspect to reveal relevant information about a crime even under severe torture, a guilty suspect is likely to crack under prolonged interrogation in isolation and make a damning confession. Activists claim that the Japanese justice system (and Japanese public to some extent) consider that prolonged interrogation of suspect in isolation without access to lawyers is justified to solve the criminal cases without risking the miscarriage of justice. In addition, the requirement that the revelation of relevant information by the accused was unknown to the police and that the prosecutor examines the police investigation before the case is brought to the court, is seen as an extra layer of safeguard for the validity of confession as evidence.
However, most miscarriage of justice cases in Japan are, indeed, the results of conviction solely based on the confession of the accused. In these case, (1) the record of sequence and timing of the police discoveries of evidence and the timing of confession is unclear (or even faked by the police) (2) the contents of the revelation of secret has only weak relevance to the crime itself or that (3) the revelation of secret to be actually vague enough that it is apply only loosely to the elements of crime (Prosecutor's fallacy). Serious miscarriage of justice cases in Japan involve police deliberately faking the police evidence (and insufficient supervision by the prosecutor to spot such rogue behaviour) such as where the police already knew (or suspected) the location of the body or the murder weapon but they fake the police record to make it appear that it is the suspect who revealed the location. During the 1970s, a series of reversals of death penalty cases brought attention to the fact that some accused, after intensive interrogation signed as-yet unwritten confessions, which were later filled in by investigating police officers. Moreover, in some cases, the police falsified the record so that it appear that the accused confessed to the location where the body was buried, yet the truth was that the police had written in the location in the confession after the body was discovered by other means. These coerced confessions, together with other circumstantial evidence, often convinced judges to (falsely) convict.
Currently the Japanese Federation of Bar Associations is calling for the entire interrogation phase to be recorded to prevent similar incidents occurring. The International Bar Association, which encompasses the Japanese Federation of Bar Associations, cited problems in its "Interrogation of Criminal Suspects in Japan". Japan's current Minister of Justice, Hideo Hiraoka, has also supported videotaping interrogations. Police and prosecutors have traditionally been opposed to videotaping interrogations, stating that it would undermine their ability to get confessions. The current office of prosecutors has, however, reversed their previous opposition to this proposal. Proponents argue that without the credibility of confessions supported by electronic recordings, the lay judges may refuse to convict in a case when other offered evidence is weak. It is also argued that recording of interrogation may allow lowering standard in the "revelation of secret" that confession must contain the element of crime which police and prosecutor did not know. Once the recording is introduced, it would become impossible for the police to forge confession. Then, it may become possible to bring conviction based on confession of elements of crime which only perpetrator "and" police knew.
In October 2007, the BBC published a feature giving examples and an overview of "'Forced confessions' in Japan". The case was called "Shibushi Case". In addition, Hiroshi Yanagihara, who was convicted in November 2002 for attempted rape and rape due to forced confession and the identification by the victim despite an alibi based on the phone record, was cleared in October 2007 when the true culprit was arrested for an unrelated crime. The two cases damage the credibility of Japanese Police.
To Japanese citizens and police, however, the arrest itself already creates the presumption of guilt which needs only to be verified via a confession. The interrogation reports prepared by police and prosecutors and submitted to the trial courts often constitute the central evidence considered when weighing the guilt or innocence of the suspect.