Residents in Tadamon said that executions in the area were common. In interviews in 2022, they described at least 10 other incidents of summary killings between August 2012 and January 2014 in Tadamon, Daraya, Moadamiya, and surrounding areas. This evidence suggests that other bodies were buried in and around the area. The area was also the site of armed clashes between Syrian government forces and opposition fighters affiliated with the Free Syrian Army (FSA) at numerous points between 2012 and 2013.
Human Rights Watch began investigating the massacre in October 2021, after receiving a leaked video discovered by a member of a Syrian militia on a laptop and handed to Annsar Shahhoud and Uğur Ümit Üngör, researchers at the University of Amsterdam and the NIOD Institute for War, Holocaust and Genocide Studies in Amsterdam, and ARD, a German Public Broadcaster.
“This video, filmed by the perpetrators themselves who laughed as they killed their victims, shows the Syrian government’s callous disregard for people’s lives,” Zayadin said. “This massacre is just one horrific incident in a pattern of state violence and apparent war crimes.”