On 17 February 2013, the Canadian national Carl Campeau, who had been working as a legal adviser to the UN forces (UNDOF) in the Golan Heights, was abducted and detained near Damascus. The abduction was allegedly committed by the terrorist organization Jabhat al-Nusra, the al-Qaeda-linked terrorist organization. As a member of Jabhat al-Nusra, Suliman Al-S. allegedly participated in the abduction by keeping the victim under surveillance between March and June 2013. Campeau was held captive for 8 months until he managed to escape in October 2013. During this time his captors threatened to kill him and unsuccessfully attempted to obtain a ransom for his release. Al-S. arrived in Germany in 2014 and was later granted asylum.
On 21 January 2016, the Syrian national Suliman Al-S. was arrested in his apartment in Stuttgart on suspicion of war crimes committed during the Syrian civil war. On 27 June 2016, Al-S was charged with committing a war crime against humanitarian operations (Section 10 (1) (1) of the German Code of Crimes against International Law (CCAIL)) for directly attacking personnel involved in a humanitarian assistance or peacekeeping mission in accordance with the Charter of the United Nations, abduction for the purpose of blackmail, unlawful imprisonment, attempted blackmail and use of force or threats against life or limb, as well as membership in a foreign terrorist organization. The charges against him were filed before the Higher Regional Court in Stuttgart.
The trial began on 20 October 2016. On 20 September 2017, the Higher Regional Court in Stuttgart found Suliman Al-S. guilty of aiding and abetting kidnapping of an employee of the United Nations in Syria in February 2013. He was sentenced to 3 years and 6 months in prison while the Prosecutor requested seven years of imprisonment for Al-S. The charges of membership in a terrorist organization were not sufficiently proven and therefore lifted. The prosecutor appealed the decision concerning the punishment, specifically the length of imprisonment. The appeal trial was held in 2018. On 23 January 2019, the Stuttgart Court of Appeals changed the punishment and prolonged the imprisonment of Suliman Al-S to 4 years and 9 months.