Prowling and preparing to kill: Chilling moment off-duty officer calmly patrols behind Russian ambassador, checks his holster twice, then pulls out his gun and assassinates him

The assassin who gunned down Russian ambassador to Turkey Andrey Karlov has been named as a Turkish police officer named Mevlut Mert Altintas, pictured, who was killed afterwards 
Altintas, pictured left, stood behind Ambassador Karlov, centre, as he began his speech before shooting him dead 
Altintas, pictured left, stood behind Ambassador Karlov, centre, as he began his speech before shooting him dead 
Russian media on Tuesday reacted with outrage to the killing.
'The murderer was afraid to look him in the eye,' ran the banner frontpage headline on pro-Kremlin paper Izvestiya above a dramatic picture of Karlov with his killer looming behind.
'They did not shoot at Karlov. They shot at Russia,' Senator Konstantin Kosachev said in comments published alongside.
Karlov was at the opening of a Russian photography exhibition in Ankara with his wife when Altintas crying 'Aleppo' and 'Allahu Akbar' (God is greatest) unleashed his attacker.
The killer had staked out the scene of the shooting exactly one week before, reports say.
Both Russian leader Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan called the attack a 'provocation' aimed at sabotaging ties that have been patched up since a furious dispute over Ankara's downing of a Russian jet in Syria in November 2015.
Putin also said that the killing in Ankara was designed to undermine efforts to find a settlement on the conflict in Syria that are currently being spearheaded by Russia and Turkey. 
The gunman claimed the assassination was because of Russia's actions in Aleppo. He reportedly shouted in Turkish: 'Don't forget Aleppo! Don't forget Syria!' 
The gunman claimed the assassination was because of Russia's actions in Aleppo. He reportedly shouted in Turkish: 'Don't forget Aleppo! Don't forget Syria!' 
Marina Karlov mourns her husband laying her head on top of his flag-wrapped coffin  during a ceremony at Esenboga airport
Marina Karlov mourns her husband laying her head on top of his flag-wrapped coffin during a ceremony at Esenboga airport
Marina broke down at her husband's coffin. 'My husband did not do anything wrong, nobody even put any threats against him, I would have known,' she told the secret services after the shooting 
Marina broke down at her husband's coffin. 'My husband did not do anything wrong, nobody even put any threats against him, I would have known,' she told the secret services after the shooting 
The flag-wrapped coffin of late Russian Ambassador to Turkey Andrei Karlov is carried to a plane during a ceremony at Esenboga airport in Ankara on Tuesday
The flag-wrapped coffin of late Russian Ambassador to Turkey Andrei Karlov is carried to a plane during a ceremony at Esenboga airport in Ankara on Tuesday
In an interview with Izvestiya, the head of Russia's parliamentary committee on foreign affairs, Leonid Slutsky, warned those who try to drive a wedge between Russia and Turkey would fail.
'The main thing is that there will not be a new round of tensions between Russia and Turkey, no matter how much our opponents want this,' he said.
'This was a terrible tragedy, but interstate relations overall will not suffer from this.'
Other outlets were, however, harsher toward Ankara - which state television had portrayed as Russia's top foe in the wake of the jet's downing - pointing out that Turkish authorities had been unable to protect the Russian envoy.
'Responsibility for the death of a foreign ambassador on its territory always lies with the host country,' Moskovsky Komsomolets tabloid wrote, adding that the murder was 'yet another powerful blow' to the reputation of Turkish President Recep Tayyip Erdogan.