THE Great Tonbridge Robbery was a heist at once familiar and extraordinary. It was the latest chapter in a tale of cops and robbers that is embedded deep in our cultural heritage, but a crime unlike any before it; a theft tailor-made for the 21st century.

The clichéd language of crime was lying in wait for the gang the moment that the lorry loaded with up to £50 million sped into the Kent night: “Fort Knox”, “military precision”, “The Firm”, “blaggers”, and “armed to the teeth”. Here was a story of masked robbers, brutality and criminal daring, echoing every British heist from the Great Train Robbery to the IRA raid on the Northern Bank in Belfast in 2004.

As if Hollywood had already written the script, the day after the robbery a woman aged 41 was arrested while trying to open a building society account in Bromley, Kent, with £6,000 in cash, the bundles apparently held together with wrappers from the Tonbridge depot. Last night detectives confirmed that some of the missing cash had been found in a Ford Transit van in Ashford after a tip-off.

The stereotypes are piling up around a crime that is far from stereotypical. The crooks may be Biggs-style criminal extroverts, a new version of the Old Firm, or some unnamed criminal mastermind playing the role of Michael Caine. Criminals are just as prone to believing and acting out their own mythology as policemen, footballers or politicians.

In Britain the mythology of bank robbery is indissolubly linked to films such as The Ladykillers and Buster, featuring rogues with hearts of gold and impeccable comic timing, despite the true nature of their nefarious activities.

Two other people in Forest Hill, South London, were arrested on Thursday night on suspicion of conspiracy to commit a robbery, as detectives drew up a list of the usual suspects — the 20 or so criminals believed capable of organising such a sting — and released an e-fit of one of the men, who posed as a police officer. All three suspects were later bailed.

The Volvo used to kidnap Colin Dixon, 51, the manager of the Securitas depot in Tonbridge, was found burnt in the village of Leeds, near Maidstone. Two criminals posing as police in the dark Volvo, a blue light flashing behind its grille, intercepted Mr Dixon as other members of the gang seized his wife and son. Mr Dixon’s Nissan was found parked in the Cock Horse pub at Detling, and a red van used in the abduction was found in another pub car park near Maidstone. The white Renault lorry filmed driving off with the stolen money has still not been located.

Assistant Chief Constable Adrian Leppard did not hide a certain grim admiration for the efficiency of the crooks. “This is organised crime at its top level,” he said.

If reaction to the crime is following a familiar pattern — outrage, tinged with a sly admiration at the scale and skill of the exploit — the theft itself has entered uncharted territory, with new criminal techniques, and new police methods to combat them.

Large-scale cash robbery was once a technical challenge: drilling through walls, short-circuiting alarms, gagging guards and stationing the get-away car. Today, the weak points in the banks’ defences are not grilles and vaults, but human beings. Stealing money is now partly a matter of psychology. The success of the Tonbridge robbers depended on terrifying Mr Dixon into opening the doors. They had studied their victim. They knew the route he took home, and how he would respond when his wife and child were in mortal danger. It did not take gelignite to blow open the vaults; it took fear, in the hostage technique known as “tiger kidnapping”, so called because of the predatory stalking that precedes it. Tiger kidnapping is the point where old-fashioned crime meets modern terrorism.

The crooks demonstrated a refined psychological cruelty. As Mr Dixon was driven to the farmhouse in west Kent where his wife and son were being held, he was forced to listen to their terrified voices over a mobile telephone. He saw his wife and son being held, and had a gun put to his head. They then drove to the depot, forced Mr Dixon to let them in, and then tied up the family along with 14 staff members.

The gang knew exactly where and when to find the most money: when the banks were at their emptiest. Despite the increased use of credit transactions, the British economy still uses about £36 billion in cash every day. The Bank of England keeps surplus notes in cash depots around the country, but the money moves in predictable waves. The Christmas period is when most money is in circulation, but February is the quietest time of the year, when surplus cash is stored at 30 cash centres, including Tonbridge.

With spending peaking at weekends, cash also tends to flow back to depots in the middle of the week. The small hours of a Wednesday morning in mid-February represented the crest of the cash wave, and the gang knew it. It seems probable that this, and other information, came from the inside.

Explore UK News

• Crime News

• Education News

• Health News

• Science News

• Scotland News

Times Recommends

• Swine flu vaccine for all as drug rushed through
• Artificial sperm and the race to build a baby
• BBC jets out stars to tout for prizes