The hunt for a serial shotgun raider who has struck fear into Worthing shopkeepers will be featured tonight on BBC show Crimewatch.
The same man has carried out nine robberies in Worthing since Christmas, threatening staff at off-licences, convenience stores and newsagents.
CCTV footage of one of the robberies will be shown on the television show tonight.
Detective Chief Inspector Mark Eyre, who is heading Operation Texan, said officers were now linking another four robberies with their inquiry.
They were at the South Farm Road Post Office on February 5, the Lyndhurst Road Post Office on February 19 and Ladbrokes in Goring on February 20 and 22.
He said: "The four we are talking about have involved a similar weapon which could bear the hallmarks of someone following a copycat series, but I like to deal with the evidence rather than conjecture.
"So far, touch wood, there have been no injuries and no shots fired. The threat does remain. I don't want to terrify people, but people need to be aware and not put themselves at risk."
Ten officers are working on the case on the streets, with six working in the incident control room and further officers from other divisions assisting.
He added: "We haven't had an incident since February 9 and we hope we don't get another, but my focus is on getting the offender responsible for these crimes.
"When there are firearms involved there always remains a very real risk that injuries or even fatalities could occur and that's why we have given a significant response to this series with support from outside the division."
There have been 17 robberies in Worthing since Christmas, 16 of them armed.
PC Peter Jones, Highdown division crime prevention officer, said: "There's a lot people can do to make their shops less likely to be robbed.
"It could involve raising staffing levels at this time of heightened risk and often stores have CCTV. It's important they are checked and recording well and tapes should not be used more than ten times.
"It's important for staff to be a little more vigilant than they have previously been and calling the police in the event of anybody answering the description in the photo."
The offender is white, in his late teens or early 20s, 5ft 6in to 5ft 10in tall and slim with a prominent nose.
He often wears a casual leisure top with a hood and a Burberry type scarf.
Crimewatch is on BBC1 at 9.05pm. Anyone with information should contact Sussex Police on 0845 6070999.
An armed raider struck at Alldays in Lower Street, Pulborough at 9.36pm last night.
He entered the shop and stole cash after threatening staff with a knife.
He was white, in his early 20s, about 6ft tall and wore beige trousers, Reebok trainers, a black hooded top and a cream scarf.
Anyone with any information is asked to call Steyning CID on 0845 6070999.
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