Blog of the International Journal of Constitutional Law

Japan Supreme Court Limits Police GPS Surveillance, Citing Constitution Article 35

–Lawrence Repeta, Member, Japan Civil Liberties Union and former Professor, Meiji University

On March 15 of this year, the Supreme Court of Japan issued a rare decision that limits the authority of the police to conduct surveillance operations. The case involved the placement of GPS tracking devices on the vehicles of surveillance targets. According to the published Supreme Court opinion,[1] for a six and a half month period that commenced in May 2013 police investigators placed GPS tracking devices on no fewer than 19 vehicles used by the target of the investigation, accomplices, and acquaintances.

The appellant was found guilty by both the district court and intermediate appellate court prior to his Supreme Court appeal, but the decisions of those two courts were distinguished by their rulings on the issue of GPS surveillance. According to the District Court, police must obtain a judicial warrant to authorize their use of GPS tracking.[2] The District Court excluded the GPS data from consideration, but nonetheless convicted the defendant on other evidence. The High Court disagreed, stating that at the time of the investigation, Japan’s courts had not established clear precedents requiring warrants and therefore the police action did not rise to a level of illegality sufficient to require the GPS evidence to be excluded from consideration.

The unanimous ruling by all 15 justices upheld the guilty verdict, but unequivocally overturned the High Court regarding the legality of GPS surveillance.

In a key passage the Court explained:

Because this kind of investigative method inevitably enables (the police) to grasp the continuous and comprehensive acts of an individual, it can violate the privacy of that individual; moreover, because this kind of violation is made possible by the secret installation of a device on individual property, it differs from methods such as observing an individual’s location on public streets by the naked eye or through photography.  We must say that it involves penetration of private space by public authority.

The Court followed by issuing a historic interpretation of critical language in Constitution Article 35, which protects individual rights “to be secure in their homes, papers and effects against entries, searches and seizures.” The Court stated that this protection extends not only to “homes, papers, and effects,” but also protects against “entries” to other private areas (korera ni junzuru shiteki ryōiki). Professor Makoto Ibusuki quickly declared that a new legal term, shiteki ryōiki or “private space” was born. Illustrated by placement of GPS devices on vehicles, this private space is not limited to homes and other buildings, but includes vehicles which can move about in a broader public space. Professor Ibusuki labelled the decision epochmaking (kakkiteki) and expressed the hope that the concept might be expanded in future decisions.[3]

In cases like the present where it can be presumed that the police action was taken against the will of the target, the Court explained that in the light of the “important legal interests protected by the Constitution,” unless there is a specific provision of the criminal procedure law, it constitutes a “compulsory action” (kyōsei shobun) which requires the police to obtain a judicial warrant. Because there is currently no specific provision in Japan’s criminal procedure law authorizing such warrants, the effect of this decision is to prohibit the use of GPS tracking. The Court effectively lobbed the ball into the legislative court. If Japan’s police really need GPS tracking, the Court suggested they must persuade the Diet to pass a new statute, much like the wiretapping law.[4]

Despite the Court’s rejection of the police efforts to employ GPS without warrants, observers concerned about excessive police surveillance may find little comfort in the GPS decision. The Court was careful to distinguish the placement of GPS devices from other common surveillance techniques; in the Court’s words “it differs from methods such as observing an individual’s location on public streets by the naked eye or through photography.” Police use of camera surveillance has been exposed in several cases. The most noteworthy concerns comprehensive police surveillance of Muslims.[5] Just last year the Supreme Court upheld lower court rulings approving surveillance of an entire community based on religious affiliation, without any evidence of wrongdoing. There have been other recent cases that suggest such police surveillance may be employed for political purposes.[6]

Suggested Citation: Lawrence Repeta, Japan Supreme Court Limits Police GPS Surveillance, Citing Constitution Article 35, Int’l J. Const. L. Blog, Aug. 16, 2017, at:

Note:  All translations were made by the author and unless otherwise noted, all material cited is in Japanese.


Article 35. The right of all persons to be secure in their homes, papers and effects against entries, searches and seizures shall not be impaired except upon warrant issued for adequate cause and particularly describing the place to be searched and things to be seized, or except as provided by Article 33.

Each search or seizure shall be made upon separate warrant issued by a competent judicial officer.

[1] Available at

[2] The court held GPS tracking to constitute a “compulsory act” (kyōsei no shobun) under Article 197(1) of Japan’s Code of Criminal Procedure.

[3] Makoto Ibusuki, “The age of surveillance and privacy” (kanshi no jidai to puraibashi), Sekai, June 2017, 46-54.

[4]  For a report on recent developments in wiretapping authority, see “Expanding scope of wiretapping,” Japan Times editorial, October 7, 2016, available at (English)

[5] See “Spying on Muslims in Tokyo and New York — “Necessary and Unavoidable”? Asia-Pacific Journal Report, (English)

[6] E.g., “Hidden cameras on the grounds of an office connected to the Minshinto” (kakushi camera, “minshintō” kanren tatemono shikinai ni), Mainichi Shimbun, Aug. 3, 2016. (Police surveillance cameras recorded persons entering the offices of an opposition political party during an election period in Oita prefecture in 2016.)  E.g., “If the bill passes, increased surveillance is certain” (hōan seiritsu nara, kanshi no kyōka kakujitsu), Tokyo Shimbun, Feb. 4, 2017.  (Police surveilled a local citizens group that demonstrated against a proposed wind farm and delivered dossiers on the activists to a subsidiary of Chubu Electric, the power company behind the project.) There are other published reports on surveillance by the Self-Defense Forces and the Public Security Intelligence Agency.  Regarding the latter, see Lawrence Repeta, “Japan’s Bar Associations and Human Rights Protection,” available at (English).


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