A BBC Arabic investigation has uncovered compelling evidence suggesting the Syrian-Kurdish political leader, Hevrin Khalaf, was executed by a faction of the Turkish-backed Syrian National Army. Rebel group Ahrar al-Sharqiya, which fights for the SNA, is accused of her murder, but has told the BBC it is not responsible for the politician’s death. But by speaking to members of Ahrar al-Sharqiya, as well as Hevrin Khalaf’s family, former colleagues and an eyewitness, plus using open source investigation tools, the BBC has discovered a different story about what happened on 12 October 2019. The Turkish government, which backs the Syrian National Army, has not responded to BBC requests for comment. Video produced by: Nader Ibrahim, Rosie Garthwaite and Mustafa Khalili. Graphics by Jasmine Bonshor.