A man who has committed a string of city robberies going back at least 16 years threatened a terrified shop assistant with an imitation gun in an armed hold-up at a Co-op store, a court heard.

Norwich Evening News: Co-op store on Catton Grove Road, Norwich. Photo: GoogleCo-op store on Catton Grove Road, Norwich. Photo: Google (Image: Google)

In his latest attack, Ryan Smith, 42, walked into Co-op on Catton Grove Road on July 9 and lifted his coat revealing what looked like the handle of a firearm before threatening a shop assistant and escaping with cash.

Smith was later arrested after armed officers visited a house on Burges Road in Norwich.

Smith, of Woodcock Road, Norwich, who appeared at Norwich Crown Court via a video link from prison, admitted robbery and possession of an imitation handgun.

The case was adjourned for sentence but the court was told he had a number of previous convictions for similar offences and in December 2013 was jailed for six years for holding-up two shops in Norwich on the same day.

Smith held up Arts Desire on St Benedict's Street and later that day carried out a robbery at Vintage Clothing in Unthank Road, where he fled with £20.

Judge Stephen Holt said that it must have been a 'very traumatic experience' for the staff at the Co-op in the latest robbery and said he did not know if any of them might want to attend to see him sentenced.

He said: 'I have no idea if the victim of the robbery will want to attend.'

He told Smith that his biggest piece of mitigation was his guilty pleas, which saved anyone having to give evidence.

His case was adjourned until September 5.

Smith was arrested for the previous robberies in 2013 after a retired detective read a report in the EDP and recognised the offences were strikingly similar to those carried out by someone he had arrested back in 2002 for robberies on a number of shops including Ginger on Timberhill and the Co-op on Dereham Road.

Neal Carr, who was a police officer for 30 years and served on Norwich CID for 26 years, had arrested Smith in 2002 and Smith was jailed for nine years.