For more information on the Ousman Sonko case and the appeal proceedings, see our press release and Q&A (available in English, French and German).

Week 1: (30 March – 2 April) The Appeal Trial Begins

> Days 1 and 2 (30 and 31 March): Preliminary questions <

 
At the opening of the trial on 30 March 2026, the presiding judge confirmed who was present:

• the Office of the Attorney General (OAG);
• Ousman Sonko and his lawyers, and;
• 5 plaintiffs who had travelled to Bellinzona, along with their lawyers.

The floor was then given to the parties to present their preliminary questions.

• Admissibility of the appeals and validity of the amended indictment

The defence argued that the appeals filed by the OAG and the lawyers for the plaintiffs were inadmissible, on the basis that the indictment did not describe the relevant facts with sufficient detail (particularly regarding sexual violence) and could therefore not be examined.

It also challenged the validity of the amended indictment (July 2023), arguing that the original version did not include charges of sexual violence or the factual elements supporting the aggravated charge of crimes against humanity, which, in its view, was a decision not to charge Mr Sonko with these crimes. The defence further claimed that the amendment was improper, as the OAG was ordered to modify the indictment.

The OAG and the lawyers for the plaintiffs rejected these arguments. The OAG maintained that the amended indictment was valid, complied with legal requirements, and contained sufficient factual detail to allow the Court to examine all issues.

• Sexual violence as crimes against humanity

The lawyers for the plaintiffs argued that Switzerland should be able to prosecute acts of sexual violence as part of crimes against humanity, which had been discontinued in first instance.

They also argued that these acts could be prosecuted as torture, giving Switzerland ratified the Convention against Torture which imposes an obligation to prosecute, and that the requirement of double criminality (requiring that torture be punishable both in Switzerland and in The Gambia at the time of the facts) was met.

Challenging the first-instance judgment, they argued that there was evidence showing that sexual violence formed part of a broader pattern of repression, rather than isolated acts. They further stressed that even a single act of sexual violence can qualify as a crime against humanity if it is linked to a wider or systematic attack against civilians, and maintained that this was the case, as Mr Sonko acted in that context, taking advantage of his position and the vulnerability of the survivors.

• On Switzerland’s jurisdiction

The defence challenged it, arguing that crimes against humanity were not codified in Swiss domestic law prior to 2011, and that, for the facts alleged in the indictment between 2000 and 2006, no consensus existed among States as to their definition or any obligation to prosecute these crimes.

The OAG responded that Switzerland could prosecute crimes against humanity committed before 1 January 2011 based on customary international law, and that none of the charges were time-barred.

• On reparations

The defence contested that, because Mr Sonko does not have an established domicile or habitual residence in Switzerland, the first instance and the present Court could not rule on the reparations awarded to the plaintiffs in the first instance.

The lawyers for the plaintiffs argued that jurisdiction was established through Mr Sonko’s link to Switzerland via his asylum application.

• On accessibility

The defence argued that Mr Sonko had not been able to understand the first-instance proceedings, and that the judgment (both oral and written) had not been translated into a language he understands. This violated his rights under the European Convention on Human Rights, and therefore it asked for the appeal trial to be suspended until this was rectified through the full translation of the first instance judgment.

The lawyers for the plaintiffs acknowledged the lack of translation at first instance (which prevented Gambian media to properly follow the proceedings), but argued that the current interpretation on appeal exceeded usual practice and that the defence’s request to suspend the proceedings was unfounded.

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> Day 3 (1 April): Ongoing procedural matters and motions <

The Court rules on preliminary questions

The Court ruled that the law does not require a full translation of the judgment. It also noted that the defence had already translated many documents into English during the proceedings, meaning that Mr Sonko had been able to understand the charges against him and the judgment.

The Court also rejected the defence’s objections to the admissibility of the other parties’ appeals. It also confirmed that the amended indictment was valid and that it would examine the case on that basis.

On jurisdiction, the Court found that Switzerland could, in principle, prosecute acts committed before 1 January 2011, but noted that this would be confirmed when it examined the case in full.

On the matter of reparations, and Mr Sonko’s residency status, the Court found no reason at this stage to conclude it lacked jurisdiction.

Finally, the Court stated that it would assess, when examining the case as a whole, whether the acts qualify as aggravated crimes against humanity, including sexual violence and the detention of certain victims in 2016. It also stated that certain acts would be assessed as acts of torture of a sexual nature and as violations of sexual integrity.

Two motions from the defence

• Inconsistencies in translations

The defence pointed out that the translation of the indictment was inconsistent, as Mr Sonko’s alleged acts were described both in terms of complicity and co-perpetration. It asked for the indictment to be read out in full, or for the OAG to clarify Mr Sonko’s alleged role in the crimes.

The Court rejected the request, noting that the indictment had already been provided in German and English and that the charges had been explained during the first instance trial. It clarified that the charges concern co-perpetration, and not complicity.

• On the hearing of a witness

The defence argued that the planned witness hearing involved disputed evidence. It asked the Court to decide on the admissibility of that evidence before the witness hearing, or not refer to it during questioning.

The Court decided that it would be examined after the witness hearing, and if any of the evidence were found inadmissible, the related questions would be removed from the record.

Further preliminary questions on evidence

The defence requested that certain evidence be removed on the following basis:

• Lack of transparency in the investigation

The defence argued that some investigative steps had been carried out in secret or outside the legal framework. It discussed particular missions by the OAG and police to The Gambia that were, according to defence, not properly documented, as well as concerns that some witnesses had been informally questioned before their official interviews. It also suggested that evidence from The Gambia may have been selectively included, and that local authorities may have influenced what was shared with Switzerland. It exhorted the Court to investigate this, as the judges in the first instance had not.

• Evidence from asylum procedures

The defence argued that Swiss asylum authorities had continued to return Gambian nationals during the time period covered by the indictment, suggesting that the situation in the country did not amount to a widespread attack against civilians, contrary to the OAG’s account of the context. It therefore requested that a representative of the asylum authorities be heard, and that relevant reports, and communications be added to the case. It also maintained that NGO reports alone, on the violations of human rights in The Gambia, were not sufficient for the Court to form its assessment.

• Witness hearings and right to be heard

The defence argued that during the investigation, certain witness hearings had not allowed Mr Sonko to ask all relevant questions, in violation of his right to be heard. It requested that the related records be removed from the case file, or at least not relied upon.

The defence then requested that several individuals be heard, including former members of the Jammeh government and judiciary, who could provide insight into how power functioned under Yahya Jammeh. It also requested that internal state documents from The Gambia be provided.

Position of the OAG

The OAG recalled that the lower court had excluded evidence from the accused’s asylum procedure because administrative proceedings follow different rules than criminal cases (whereas the latter provides for the right not to self-incriminate, the former imposes a duty to cooperate).

However, the OAG disagreed with this approach. It argued that such evidence should not be automatically excluded, but assessed on a case-by-case basis.

In this case, it said the documents were useful to help establish crimes under international law and should therefore be taken into account by the Court, unlike what had been previously decided in the first instance.

Position of the lawyers for the plaintiffs 

The lawyers requested that some plaintiffs be heard again. They also asked for expert witnesses on the Gambian context and on gender-based violence, which would help the Court understand the stigma surrounding sexual violence in The Gambia: how it was used as a tool of repression under Jammeh, and how it was closely linked to the broader attack against the population.

They further requested that relevant reports be admitted into the case file so that the Court could make a fully informed assessment.

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> Day 4 (2 April):  Witness Hearing via Video Link from The Gambia <

 
The day was dedicated to the hearing of a witness via video link from The Gambia. The witness, a former soldier of the Gambian army, had previously testified before The Gambia’s Truth, Reconciliation and Reparations Commission (TRRC) in August 2019. During that testimony, he stated that he had taken part in the operation that led to the death of AM, an individual mentioned in the indictment, in January 2000. He has also been described as having participated in acts of torture against individuals accused of involvement in a coup attempt in March 2006.

The witness said he knew Mr Sonko well and that he was a very good commander. He last had contact with him in 2008.

He explained that he had heard allegations that Mr Sonko had raped AM’s wife repeatedly, but he found it implausible.

The witness described how he was informed of a planned coup in January 2000, and he was given the order to arrest AM, who was killed after resisting arrest. He recounted that both Mr Sonko and Landing Sanneh (former commander of The Gambia’s presidential guard) were present, and that AM had started shooting first.

When confronted with the fact that, in proceedings against Landing Sanneh in 2001 in The Gambia, Mr Sonko had testified that the guards had fired first, the witness said he had not been aware of that testimony until now and maintained that AM had fired first. After reviewing the relevant court document, he stated that Sonko’s testimony was accurate.

The witness concluded by stating that Yahya Jammeh respected and cared for his people, in contrast to the current government.

Debates on evidentiary requests 

The defence argued that some documents that had been seized from the asylum centre where Mr Sonko was staying did not belong to him, and that it had not been informed of the search that led to the discovery of such documents: therefore, they should be excluded from the case file.

On the matter of sexual violence, the defence argued that the evidentiary requests raised by the lawyers for the plaintiffs should be rejected, on the basis that the issue was not relevant in assessing if there were widespread or systematic attacks against the civilian population.

The lawyers for the plaintiffs responded that the defence could not rely on Swiss asylum return decisions to assess whether a widespread or systematic attack had taken place in The Gambia, describing such reasoning as unfounded. They also stated that they did not oppose the hearing of additional witnesses requested by the defence.

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The appeal trial will resume on 7 April, 2026.

This summary is provided for information purposes only. It is based on notes taken during the hearings and does not constitute an official court record.