Dramatic video shows the moment a group of robbers smashed through the front of a jewellers in a Range Rover before one was stopped by have-a-go heroes.
Ben Wegener and two other men used sledgehammers to shatter glass display cases, before helping themselves to valuables worth thousands of pounds.
The terrified shop owner and customers were threatened with violence during the shocking attack.
Police say it is lucky no one was seriously injured in the incident in West London.
Wegener, 34, was jailed for 10 years after admitting robbery, dangerous driving, the possession of an offensive weapon, criminal damage and receiving stolen goods.
He was arrested at the scene after being stopped by members of the public, but the two other men escaped and have still not been located.
Police later discovered that the car used by the trio had been stolen, and its number plates were changed.
The robbery happened in Shepherds Bush in West London on October 25 last year, shortly before 5.30pm.
Detective Constable Sam Weller of the Central West Robbery Squad, who led the investigation, said: “This was a reckless robbery committed in front of shoppers on a busy high street.
“It was sheer luck that no one was seriously injured when the vehicle smashed through the shop front, and the shop owner and customers were threatened with serious violence when the robbers where inside.
“The raid was thwarted by members of the public who chased down and held Wegener as he tried to escape.
“This was a terrifying incident for the victims and everyone who witnessed it unfold, and Wegener will now spend a significant period of time in jail.”
DC Weller added: “Unfortunately, his two accomplices left the scene and remain outstanding.
“We will continue to pursue leads in order to identify them, and we would urge anyone who has information about those people to contact police.”