Switzerland’s highest court has upheld a 20-year prison sentence for former Liberian rebel commander Alieu Kosiah, while simultaneously overturning a separate conviction for crimes against humanity on legal technical grounds.
The Federal Supreme Court of Switzerland issued its verdict on September 28, with the decision made public on Friday. The ruling rejects an appeal filed by Kosiah, now 51, who challenged his conviction for violations of the laws of war committed between 1993 and 1995 during the first of Liberia’s back-to-back civil wars.
While maintaining the war crimes conviction and the maximum 20-year custodial sentence, the supreme court acquitted Kosiah of crimes against humanity. The court based this reversal on a strict application of the principle of non-retroactivity, noting that the specific offense of crimes against humanity was only introduced into Swiss law in 2011 and could not be applied retroactively to acts committed in the mid-1990s.
Switzerland exercises universal jurisdiction, allowing its courts to prosecute individuals suspected of international atrocities regardless of where the acts occurred. Kosiah settled in Switzerland in the late 1990s and was subsequently arrested there in 2014.
The case stems from landmark proceedings in Switzerland’s Federal Criminal Court, which originally found Kosiah guilty in 2021 of multiple atrocities committed during the conflict that claimed approximately 250,000 lives between 1989 and 2003. In 2023, the appeals chamber upheld his 20-year sentence and expanded the ruling by finding him guilty of crimes against humanity—marking the first time a Swiss court had done so.
Legal advocates and victim representatives reacted to the supreme court’s mixed ruling with a combination of finality and disappointment. Civitas Maxima, the organization that works to bring perpetrators of international crimes to justice and represents victims in the matter, noted that the decision finalizes the first war crimes conviction ever handed down by a Swiss civilian court, as well as the first conviction anywhere of a Liberian for war crimes committed during the country’s civil conflicts.
Alain Werner, director of Civitas Maxima and representative for the victims, stated that survivors of Kosiah’s crimes have finally received justice through the upheld war crimes verdict. However, Werner expressed deep disappointment regarding the partial acquittal, asserting that the events that transpired in Lofa County between 1993 and 1995 constituted the core definition of crimes against humanity.
During the initial 2021 proceedings, the court determined that Kosiah, acting as a commander for the United Liberation Movement of Liberia for Democracy rebel faction, had ordered or directly participated in the killings of 17 civilians and two unarmed soldiers. The tribunal also found him culpable for rape, the deployment of a child soldier, ordering widespread looting, inflicting cruel and humiliating treatment upon civilians, and the mishandling of corpses.
