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Preventive Detention Under the Convention?

Recent Police Action Against Climate Activists Violates ECtHR Case Law


Preventive detention of climate activists is gradually turning into a popular practice with the German police. Recently, a video from Regensburg gained attention showing an activist of the so-called “Last Generation” being preventively detained by the Bavarian police. This prevention of an activist’s participation in a duly registered demonstration resulted in substantial criticism, but it was not the only factor raising significant concerns. In the discussion, the main concern is that such measures could violate activists’ constitutional rights. However, the violation of the European Convention on Human Rights (ECHR) and the respective case law is even more pronounced.

The relevant provision of Art. 17 (1) No. 2 BayPAG (Bavarian Police Duties Act) authorizes the police to take a person into custody “if this is indispensable to prevent the imminent commission or continuation of an administrative offense of considerable importance to the general public or a criminal offense”. Similar authorizations for preventive detention are also found in the police laws of the other German federal states. In 2013, the European Court of Human Rights (ECtHR) ruled on a case based on the comparable provision in Hesse’s police law (Ostendorf v. Germany).

Ostendorf v. Germany – the ECtHR’s Findings

In the case Ostendorf v. Germany, a supporter of the Werder Bremen soccer club who was considered by the police to be a potential instigator of violence had attended an away match in Frankfurt am Main alongside other fans. The police identified the complainant as the leader of the Bremen hooligans at the Frankfurt a.M. main train station and discovered mouth guards and gloves containing quartz sand on other fans of the same group, which could potentially indicate an intention to engage in a physically aggressive encounter with rival hooligans. The group was informed by the police that they would accompany them to the stadium and take any person into custody who moved away from the group, as they feared the commission of crimes. Subsequently, the complainant was observed engaging in conversation with a Frankfurt hooligan at a local establishment, an interaction that was construed as establishing a rendezvous for a potential confrontation. When the other Bremen hooligans left the pub, the complainant hid in the ladies’ room, was then taken into custody by the police and released about an hour after the end of the match, when both the Bremen and Frankfurt hooligans had left the stadium (para. 6 ff.).

After not being successful in domestic courts, Mr. Ostendorf filed a complaint with the ECtHR. The ECtHR dismissed the complaint and held that the detention was lawful. The court stated that deprivation of liberty was permissible under Art. 5 (1)(b) ECHR in order to compel a person to fulfill a specific and concrete obligation incumbent upon him, which he has not yet fulfilled (para. 69). The general obligation not to commit a crime in the immediate future was not sufficient for this purpose as long as no order for specific measures had been issued that had not been complied with (para. 70). However, in the case of Ostendorf v. Germany, the police had ordered the complainant to remain within his fan group and announced that he would otherwise be taken into custody. This was considered by the ECtHR to be a sufficient obligation, which the complainant acted in apparent contravention of (paras. 95 ff.).

A Lower Threshold Since S. V. and A. v. Denmark?

In Ostendorf v. Germany the Court held based on its well-established case law (paras. 67 ff.) that preventive detention must meet the standard of Art. 5 (1) (b) ECHR, while detention under sub-paragraph (c) can be justified “only in connection with criminal proceedings” (para. 68). In contrast, the ECtHR’s Grand Chamber decided in 2018 that Art. 5 (1) (c) Var. 2 ECHR can be seen as a distinct reason for the detention of a person “when it is reasonably considered necessary to prevent his committing an offence” (S., V. and A. v. Denmark, paras. 99 ff.). The Court took the case, also addressing a hooligan fight, as an opportunity to change its case law on preventive detention “in order not to make it impracticable for the police to fulfil their duties of maintaining order and protecting the public, provided that they comply with the underlying principle of Article 5” (para. 116). This is remarkable, since the requirement of Art. 5 (1)(c) ECHR provides a lower threshold for preventive detention than is required under Art. 5 (1)(b) ECHR, as discussed above.

However, the Court requires under Art. 5 (1)(c) ECHR the preventive detention to be “necessary”. Therefore, the respective authorities have to consider less severe measures and find them insufficient. Furthermore, there has to be proper balance between the right to liberty and the importance in a democratic society of preventing imminent risks. The offence that is to be prevented must be “concrete and specific” and also be “of a serious nature, entailing danger to life and limb of significant material damage” (para 161). The court found this requirement to be fulfilled in S., V. and A. v. Denmark when the police arrested the alleged instigators of an ongoing fight between around fifty hooligans in Copenhagen after less stringent police measures failed (paras. 162 ff.).

A Reasoning for ‘Last Generation v. Bavaria’?

According to ECtHR case law, for preventive detention to be lawful under Art. 5 (1)(b) ECHR, the person concerned, having been made aware of the specific acts to be refrained from, must take clear and active steps indicating that he or she would act contrary to the specified obligation. Applied to the “Last Generation” activist in Regensburg this means:

Firstly, the police must have informed the activists of the specific actions to be avoided in order to prevent committing criminal offences. This criterion might be met since activists of the “Last Generation” glue themselves to public streets to protest the government’s climate policy on a regular basis. Although there is a legal debate about the question of whether civil disobedience might be protected under the right to assembly, most courts qualify blocking streets as a criminal offense. In the Regensburg case, the respective activist announced that he would participate in a protest later the same day.

Secondly, the activist must have taken clear and active steps indicating that he would act contrary to the specified obligation by the police not to participate in criminal acts during the planned demonstration. As far as is known from press reports, the police showed up at the activist’s house to take him into custody. A previous conversation (“Gefährderansprache”) to make the activist aware of his legal obligations is not documented. Consequently, the activist could not indicate whether he would act contrary to the specified obligation. According to the ECtHR case law, this procedure would have been necessary in order to meet the strict requirements of preventive detention under Art. 5 (1)(b) ECHR.

Under the ECtHR’s recent holding in S., V. and A. v. Denmark, preventive detention can be justified under Art. 5 (1)(c) ECHR if necessary. For the Regensburg case, this threshold requires inter alia the imminent risk of a “concrete and specific” offence “entailing danger to life and limb of significant material damage” (para 161). In view of the fact that not every sit-in of the so-called Last Generation constitutes criminal coercion, but this must be examined on the basis of the circumstances of the individual case against the background of the constitutionally protected right to freedom of assembly, these requirements do not appear to be met.


In summary, there are serious doubts against the preventive detention of activists without a concrete person-related danger prognosis focusing on the activist’s action after being made aware of a possible detention. A general event-related prognosis by the police is not sufficient to justify preventive detention. The ECtHR’s criterion that the person concerned must take clear and active steps indicating that they would act contrary to the specified obligation is difficult to handle for police forces. However, the case Ostendorf v. Germany shows that the criterion has proven itself in practice. The ECtHR’s “exception” made in S., V. and A. v. Denmark does not seem to be applicable to the Regensburg case. Especially in a less dynamic situation than a hooligan fight, the Bavarian police can be expected to adhere to this fundamental rights standard.

Marius Kühne

Marius Kühne is a research assistant and PhD candidate at Ruhr University Bochum, funded by a scholarship of the Heinrich Böll Foundation. He holds a M.A. in political science and is a fully qualified German lawyer. His research focuses on criminal procedure, hate speech and police accountability.

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1 Comment
  1. Helpful insights into the Court’s jurisprudence regarding preventive detention.
    But I would argue that it ignores a crucial question: With regard to protests of the last generation in Germany, the conduct prevented by the police is not a hooligan fight, but an activity protected as freedom of assymbly under Art. 11 ECHR. How would that fact change the criteria of necessity?

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