Petra Ehnar, a shop assistant at Graff’s jewellers in Mayfair, central London, was forced at gunpoint to empty the store’s displays of gems, including a £3.5 million diamond necklace, during the raid on August 6 last year.
She was then held with a gun to her back as the robbers made their getaway in a series of vehicles, shooting at anyone who tried to impede their escape, Woolwich Crown Court was told.
Aman Kassaye, 24, and Craig Calderwood, 27, who used professional make-up artists to make them look as if they were in their 60s, deny conspiring with seven other men to carry out the robbery.
Ms Ehnar, who had been working at the New Bond Street store for less than four months, was told she would be killed if she did not carry out the robbers’ demands.
She told police: “This was the first I had ever been subjected to an armed robbery and I was petrified.
“I was thinking I am going to be shot, killed, I had no idea.
“It is the most terrifying experience a person can be put through, as you have no control over the situation that you find yourself in.”
Ms Ehnar said she grew even more concerned when she thought she heard a security guard shouting as she walked out into the street with Kassaye holding her at gunpoint.
“This worried me because I could still feel the gun being pushed into my back,” she said.
“This really worried me because I felt the men would shoot, I really did. The next thing I heard was the gun being fired and the noise was so loud. I realised I wasn’t shot because I was still in one piece.”
The jury of eight women and four men was shown footage of the moment the shot was fired in the street outside. The mobile phone footage caught raised voices and shouting as passers-by began to realise what was happening before a loud shot sent people running for cover.
Philip Bennetts, for the prosecution, told the jury: “It introduces you, does it not, to something of the atmosphere of that day and what those in the store when guns were shown and they were threatened would feel when they were forced, as they were, to hand over the jewellery.”
He went on: “The end result is that those involved succeeded in their goal.
“The terrified employees handed over the jewels, people who attempted to impede the escape were shot at, and the bag containing the jewels was handed to the waiting motorcyclist who made his escape. The robbers made their getaway, and the jewellery that they took has not yet been recovered.”
He said the robbers used a series of getaway cars for the “high-stakes” raid, which required “meticulous planning”. Several vans and trucks were used to obstruct traffic and delay police.
CCTV footage from inside the store also showed manager Martin Leggatt spreadeagled on the floor with a gun pointed at his head.
Kassaye, of no fixed address, watched the footage from the secure dock at the back of the packed courtroom along with most of the other eight defendants. But Calderwood, also of no fixed address, stared at his feet while the footage was shown.
Together the pair planned and executed the heist, entering Graff’s and stealing the gems at gunpoint, Mr Bennetts said.
Both Kassaye and Calderwood deny conspiracy to rob Graff‘s jewellers between August 3 and August 7, 2009. Kassaye also denies kidnap and possession of a handgun and sawn-off shotgun. Calderwood also denies possessing a handgun and sawn-off shotgun.
Seven other defendants all deny conspiracy to rob.
The trial was adjourned until today.