Nobody really knows by whom.
I say Israeli with extreme reverence and sorrow. Mer-Khamis was born to a Jewish mother and Arab father. It is hard to imagine a man who embodied more completely the compassion we will need to grow into peace. If you have not seen his film, "Arna's Children," about his late mother's efforts to start a theater school in Jenin in the 1990s--and the ways her charges grew into insurgents and terrorists--you will understand nothing about this conflict.
Arna was a former Palmach fighter whose physician father famously worked to eradicate malaria. She and Juliano hoped theater would help young Palestinian boys work out their feelings of rage. His film about this effort and what followed during the Al-Aqsa Intifida may also be the most convincing depiction of the pathos of revenge since "Hamlet."
Change your plans for tonight. Watch the film here, on YouTube, in tribute. Try not to watch it alone.