Mevlut Mert Altintas shot dead the ambassador at an event in Ankara before he was killed by special forces.
Altintas was filmed as he blasted the ambassador from behind with his semi-automatic handgun during the launch of a photographic expedition.
Turkish officials claim Altintas was off-duty at the time of the assassination.
Mevlut Mert Altintas, reportedly used his police security badge to gain entry to the gallery and stood behind the ambassador as he addressed the crowd.
Smartly-dressed in a black suit, Altintas shouted “Don’t forget Aleppo” and “Allahu Akbar” as he opened fire with a semi-automatic machine gun, killing Mr Karlov instantly.
Turkish authorities have arrested Altintas’ sister, mother and roommate, CNN Turk TV reports.
Gunman Mevlut Mert Altintas, and (right) his police yearbook photo.
Atlintas became a policeman in 2014 and was a member of the riot police squad in Ankara, Turkey’s interior minister Suleyman Soylu said.
A senior security official said there were “very strong signs” the gunman belonged to the network of the US-based cleric Fethullah Gulen.
Turkey’s president Recep Erdogan has denounced Gulen as a terrorist, an accusation the cleric denies.
Atlintas immediately after he shot the ambassador dead.
Suspicion could also fall on a group such as Islamic State, which has carried out a string of bomb attacks in Turkey in the last year in retaliation for Ankara’s military campaign against the militants in Syria.
President Erdogan, in a video message to the nation, cast the attack as an attempt to undermine NATO-member Turkey’s relations with Russia – ties long tested by the war in Syria.
He said he had agreed in a telephone call with Russia’s Vladimir Putin to step up co-operation in fighting terrorism.
At a special meeting at the Kremlin, President Putin ordered increased security at all Russian missions and said “the bandits” who committed the act would feel retribution.
“We must know who directed the killer’s hand.”
Terrified witnesses huddle in a corner inside the gallery where Andrey Karlov was killed.
According to witnesses inside the gallery, Mr Karlov the gunman warned journalists filming the event: ‘Stand back! Stand back! Only death will take me out of here. Anyone who has a role in this oppression will die one by one.’
Atlintas was killed by special forces. Three other people were injured in the bloody chaos of the event.
The assassination of an ambassador, not least of a major power such as Russia, marks a dangerous escalation of tension in the region and beyond. Security sources said he was off duty and some witnesses said there was no security scanning machine at the entrance.
Russia is an ally of Syrian President Bashar al-Assad and its air strikes helped Syrian forces end rebel resistance last week in the northern city of Aleppo. Turkey, which seeks Assad’s ouster, has been repairing ties with Moscow after shooting down a Russian warplane over Syria last year.
“We regard this as a terrorist act,” said Russian Foreign Ministry spokeswoman Maria Zakharova. “Terrorism will not win and we will fight against it decisively.”
Read more at http://www.9news.com.au/world/2016/12/20/10/20/the-off-duty-police-officer-who-gunned-down-russias-ambassador-revealed#XprltpvGhOLLIryF.99