LISTEN: 'Open all the tills quickly now,' robber demands
Caught in the act - a man is recorded shouting at staff to open tills at a shop as he makes off with cash during a robbery.
Now a reward of up to £10,000 has been put to help capture the man linked to a string of robberies in the Black Country and Birmingham.
Supermarkets and convenience stories were targeted by the thief during the campaign between March and November.
A man armed with a black handgun approached the tills and threatened staff and forced them to take money out of the tills before escaping on each occasion.
Shops including those in Halesowen, Stourbridge, Oldbury, Brierley Hill, and Dudley were raided.
Charity Crimestoppers and the Association of Convenience Stores have tabled the reward in a bid to find the culprit.
And detectives have taken the unusual move of releasing audio from one of the robberies of a man they suspect of being involved in the attacks.
The recording - captured on a shop security system ? has had background noises removed.
He can also be heard telling staff to 'open all the tills quickly now' before urging them to show him a back route out of the shop.
New CCTV images of two men also believed to be linked to the robberies has also been released as part of a fresh appeal for information.
The images were captured of the pair at the Sainsbury's Local shop, in Wollaston High Street, on September 12.
Detective Inspector Nigel Smith, from Dudley CID, said: "Thankfully, nobody was injured in the robberies.
"We have carried out numerous inquiries to try and identify the suspect but as yet, we have been unable to trace him.
"I am now releasing an audio recording taken from the raid on Sainsbury's Local on High Street in Wollaston.
"Hopefully someone listening to the audio may recognise the suspect's voice and call us with his identity."
A total of 12 robberies have been committed between March 30 and November 26 at nine different supermarkets and convenience stores.
All the raids took place in the evenings, between 7.45pm to 10.30pm, with one store was targeted on three separate evenings.
Police say a shop in Howley Grange Road, Halesowen, was targeted on March 30 and August 17.
A shop in Chester Road, Erdington was raided on April 13, July 8 and November 26.
On July 23 a premises in Edgewood Road, Rednal, was raided between 9.50pm and 9.55pm
Other raids in September including those in Alvechurch Road, West Heath, Birmingham, in High Street, Wollaston, and in Springfield Road, Walmley, Birmingham
Three further robberies took place in Castle Road, Oldbury, Highgate Road, Brierley Hill, and Buffery Road, Dixons Green, Dudley.
Anyone with information is urged to call police on 101 or Crimestoppers on 0800 555 111 if wanting to claim the reward of up to £10,000.
