Shocking CCTV footage has captured the moments an armed gang burst into a jewellers and beat a shop worker with a hammer before fleeing with £250,000-worth of high-end gems.
The masked robbers stormed SP Green in the Jewellery Quarter of Birmingham in broad daylight after one of them posed as a customer to trick staff into opening the door.
The five thugs then grabbed expensive items from display cabinets while, one of the gang, Owen Richardson, 21, was seen attacking a staff member with a hammer.
As the staff member was repeatedly stamped on, Daijon Johnson and Jamul Pinnock-Parkes, both 20, ransacked the store, during the raid on 6 January last year.
The gang then rushes out the building in a frenzy after another member of staff triggered a smoke shield, Birmingham Crown Court was told.
Three of the gang, Pinnock-Parkes, Johnson and a 17-year-old gang member who tried but failed to gain entrance into the jewellers, were arrested after fleeing and calling for a taxi.
The taxi driver became suspicious when the passengers hid their faces and he reversed up to a police car and despite trying to escape, the trio were arrested at the scene.
Richardson and his getaway driver Jermaine Davis, 27, were arrested in a Renault Megane spotted near the robbery.
West Midlands Police say that of the £250,000 of jewellery was taken, only £12,000 worth was ever recovered.
DC Mark Timmins, who led the investigation, said: "This was a really nasty robbery targeting a business in the heart of the Jewellery Quarter.
"Despite the gang members being disguised, we have used CCTV from around the city to ensure they have been brought to justice.
"The member of staff who was hit with the hammer was left really shaken and it's by sheer luck that he wasn't really seriously injured.
"Businesses in the area can rest assure that we will always fully investigate these crimes.
"This robbery had a considerable amount of planning, and if anyone has concerns about people acting suspiciously in the Jewellery Quarter, they can always speak to us."
Richardson was jailed for 14 years for conspiracy to rob and possession of class A drugs with intent to supply. The Newtown, Birmingham, resident had denied the conspiracy charge, but was convicted after a jury spent 11 minutes deliberating.
Johnson, from Ladywood, Birmingham, admitted conspiracy to rob, and an unrelated robbery, and was jailed for 12 years and eight months.
Pinnock-Parkes, of Selly Park, Birmingham, admitted conspiracy to rob and was jailed for nine years and 10 months.
Davis, of Edgbaston, admitted conspiracy to rob and possession with intent to supply and escaping from lawful custody. He was jailed for 14 years and 11 months.
Bradley Devine, 25, of Quinton, Birmingham, who pretended to be a customer to allow the gang access, was jailed for 10 years after admitting conspiracy to rob and other offences.
The 17-year-old, who must remain anonymous for legal reasons, will be sentenced on 15 December after admitting conspiracy to rob.