Evidence? They fucking found them. And the numbers are going to go up. (bold is mine)
https://www.bbc.com/news/articles/cj90wz8weymo
More than 100,000 people are thought to have disappeared in Syria since 2011.
In the past week, the rebel group Hayat Tahrir al-Sham (HTS) - who ousted Assad after more than 50 years of his family's rule - has opened up prisons and detention centres across Syria.
Rights group have concluded that more than 80,000 of the missing are dead. Another 60,000 people are believed to have been tortured to death, according to the UK-based war monitor the Syrian Observatory for Human Rights (SOHR).
Local people are reporting more and more locations of mass graves across Syria, and the Syrian Emergency Task Force (SETF), a US-based NGO, says that nearly 100,000 bodies have so far been found.
Rights group Human Rights Watch says such graves should be protected and investigated.
At another site in Qutayfah town, further to the north-west of Damascus, the SETF says thousands of bodies are believed to be buried in different mass graves.
One local resident, who witnessed the burial of bodies over the years of Syria's civil war, says they were packed in refrigerated containers brought in by security forces.
The ground would be filled with bodies - and then the site would be flattened by bulldozers, he told the BBC.