On 16 April 2013, the
Tadamon massacre occurred.
Syrian Ba'athist forces headed by Youssef brought around 288 civilians to a ditch prepared for cremation. The soldiers and militiamen mocked the blindfolded and bound civilians before they shot over 40 of them, including 7 women and 15 children, pretending to lead them to safety and telling them to run toward the ditch. Youssef was identified in 2021 as one of the leading perpetrators, having been recorded shooting several blindfolded and bound civilians at the ditch. and the European Union placed sanctions on him for his involvement in the massacre, followed by the United Kingdom in 2025. After the fall of the
Assad regime in 2024, Youssef hid from neighbors and authorities for over a year, moving at night between his family's rural home and the forested mountains. == Arrest ==