Turkey and Russia have launched a joint investigation into the assassination of Russia's ambassador to Turkey at the opening of a photo exhibit in the capital, Ankara, on Monday.
The ambassador, Andrei Karlov, was gunned down as he gave a speech at an art gallery. Turkey has identified the attacker as Mevlut Mert Altintas, a 22-year-old riot police officer, who shouted to the crowd, "Don't forget Aleppo! Don't forget Syria!" He was killed by Turkish special forces at the scene.