German office worker Drosten F. was just about to order lunch on a restaurant terrace on a sunny August day last year when he heard a loud bang.
At first glance at the scene unfolding before him, he thought it was an accident.
But it would turn out to be the murder in broad daylight of a former Chechen commander, a Berlin court heard Thursday, on the second day of a high-stakes trial of a Russian man accused of acting on Moscow's orders.
"I saw a man prostate on the ground, a bicycle on the floor and another man who was standing. I thought it was an accident, a burst tyre. One fell and the other was helping," said the administrative official, 38.
But the man who was standing, dressed in dark overalls, approached the other person on the ground, pointed "a long object" against his head, "and I heard the same bang," he said.
"And I understood what had happened."
Drosten F. was one of two witnesses called to the stand on the second day of the trial.
He recounted that he was not the only one who saw the killing unfold on August 23, 2019.
The terrace he was sitting at was full and he recalled hearing a woman with a child in her arms scream: "Someone is shooting".
Everyone "rushed into the restaurant, some screaming, others trying to calm each other down. We called the police."
- 'Very calmly' -
Another customer at the restaurant, Andreas R., also recalled the sudden bangs that rang out.
While he didn't see the actual shooting, he said he saw the suspected killer leave the scene "very calmly" with his bicycle.
"I decided to follow him, at a good distance. But I stopped when I saw the victim face down on the ground. There was blood everywhere," said the employee at the court of audit, 50.
Neither of the witnesses saw the suspect's face.
A 55-year-old Russian national named by prosecutors as Vadim Krasikov, alias Vadim Sokolov, stands accused of gunning down 40-year-old Georgian national Tornike Kavtarashvili in the Kleiner Tiergarten park in central Berlin.
The defendant has so far stayed mum over the case, but German prosecutors have alleged that Russia ordered the killing.
Russia has denied all allegations.
On Thursday, Moscow accused Germany of having pre-conceived ideas on who was behind the killing.
"There is no doubt that ... the blame for the fatal attack ... will be placed, as it has been already stated in the press, on Russia state structures," charged Russian Foreign Ministry spokeswoman Maria Zakharova.
But the brazen murder in the heart of the German capital appeared to be a tipping point for Chancellor Angela Merkel, who said in May that the killing "disrupts a cooperation of trust" between Berlin and Moscow.
The trial, which is adjourned until October 27, will continue to hear from witnesses in the next sittings, with prosecutors to then present their proof detailing their theory of Russian implication.
Putin has described the victim as a "fighter, very cruel and bloody" who had joined separatists against Russian forces in the Caucasus and also been involved in bombing attacks on the Moscow metro.
Moscow also said it had been seeking his extradition.
Named as Zelimkhan Khangoshvili by German media, the victim had survived two assassination attempts in Georgia.
Following that, he sought asylum in Germany and had spent the past years in the country.