An armed robber dubbed "Cap Man" due to his trademark headgear has held up at least 24 banks, building societies and betting shops during the last decade, detectives revealed last night.
The prolific offender - whose crime spree was outlined on Crimewatch UK - has struck in Derbyshire, Nottinghamshire, Staffordshire, Warwickshire, Buckinghamshire, Worcestershire, the West Midlands, Northamptonshire, Gloucestershire and Cambridgeshire.
Bizarrely, investigations co-ordinated by West Mercia Constabulary, which is leading the hunt for the raider, have found that he is most likely to strike on a Tuesday.
Cap Man's typical modus operandi is to wait until there are no or very few customers inside a bank or building society and then approach the cashier claiming he has a gun which is hidden in a bag.
Detective Inspector Paul Williamson, of West Mercia Police, said: "No weapon has been seen but the offender appears to carry a long cylindrical item in a carrier bag.
"Although this man has so far not injured anyone, he has threatened violence and it is vital we catch him as soon as possible."
The robber is described as black with a light complexion, aged 30 to 40, of stocky build and is 5ft 9 to 5ft 10ins tall.
He also has a distinctive spot on his right cheek, about level with the middle of his nose, which could be a birthmark or mole.