It is 50 years ago today that a Kent island became the focus of a search in one of the UK's largest-scale manhunts.

The episode was sparked by the murder of one of the highest-ranking police officers in England at the time as he tried to arrest robbers – leading to a 45-day chase for his killer which would see the Isle of Sheppey take the national spotlight.

In a new book "In Justice, Love and Honour", author Stephen Gillen has detailed the remarkable tale, which saw police Superintendent Gerald Richardson shot dead on August 23, 1971.

The ensuing chase for his killer and one of the other robbers involved in the dawn-raid saw a Sheppey chalet and caravan parks in Leysdown searched, before the focus of the manhunt switched to London.

Mr Gillen, 50, was inspired to write the book after being contacted by Joseph Loney. His father, Joseph Loney Snr, was later to have an involvement in stopping 'Fat Fred' breaking the law once again.

“The more I heard about this story, the more I thought it had to be told,” said Mr Gillen, whose first book ‘The Monkey Puzzle Tree’, written about his life, is being adapted for the big screen in Hollywood.

Fat Fred, whose full name is Frederick Joseph Sewell, had been a part of a group of armed robbers who targeted jewellers in Preston, with this week marking the 50th anniversary of that fateful morning.

He was accompanied by nightclub owner Charles Haynes, Dennis Bond, Thomas Flannigan and John Spry.

But the robbery went terribly wrong.

Fleeing the jewellers, precious gems, gold and watches were left on the pavement, and after knocking unconscious a passer-by who tried to intervene, the robbers found the doors to the getaway Triumph car locked - just as police cars started arriving.

What transpired next saw three policemen shot – and Supt Richardson killed.

Officers chased their car through Blackpool, eventually ramming the car and then taking up the chase on foot. Two officers had already been shot by two of the robbers at this point.

Spry shot PC Ian Hampson in the chest as he tried to move from his car seat as the raider escaped from the crashed car. Sewell, Spry and Bond raced down a side street, with Sewell firing at PC Carl Walker and hitting him in the groin.

The robbers then commandeered a butcher’s van which, after another high-speed chase with shots being fired out the windows, crashed into a wall and was, once again, rammed.

This time, as Sewell jumped out of the van and tried to escape, he was accosted and held by Supt Richardson. The pair grappled, with Supt Richardson fearlessly intent on arresting Sewell.

It was then Sewell shot him twice in the stomach at close range.

Haynes, who had also jumped free of the vehicle, fired a wild shot and merged into the crowd of onlookers.

Spry, who had attempted to shoot another policeman, and Bond were wrestled to the ground by other officers.

Irene Jermain, Sewell’s girlfriend, drove Sewell and Haynes to London in a getaway vehicle, starting an exhaustive manhunt, as Supt Richardson, 38, was left fatally wounded. An estimated 100,000 people lined the streets of Blackpool for his funeral and he was buried in Layton Cemetery.

The Gerry Richardson Trust has since been set up in his memory and, in 2016, a stone to commemorate him was unveiled to mark the 45th anniversary of his death.

And on Monday, to mark 50 years since his passing, a framed photo of Supt Richardson was unveiled at the headquarters of the Police Superintendents' Association. A special ceremony saw the tribute revealed at the association's newly-refurbished headquarters in Pangbourne, Berkshire, with group president Paul Griffiths and and former association national secretary Ron West photographed with the picture.

A whopping £10,000 reward, nearly £150,000 in today’s money according to Mr Gillen, was offered to catch 'Fat Fred' and Haynes, while wall-to-wall coverage was given on TV and in the press.

The focus turned to Sheppey following a tip-off the two gang members had been sighted on the Island.

A report from The Sheerness Times Guardian read: “The hunt for the killer of police superintendent Gerald Richardson switched from Blackpool to Sheppey after a tip-off gang members may be hiding out in a chalet at the eastern end of the Island.

"Supt Richardson was shot at point-blank range when he grappled with a jewel thief who was part of a five-man gang led by ‘Fat’ Fred Sewell.

“Every police force in the country was on alert, and teams of officers made a one-by-one chalet and caravan search here without success.

“Supt Richardson received a posthumous George Cross, and a memorial was made to him in Blackpool and a street named after him.”

A further report said caravan parks in the Leysdown area on the island were scoured on the Wednesday, two days after the murder.

Mr Gillen, himself a former prisoner who has since dramatically turned his life around, said Haynes and Sewell were known to have connections on the Island, with Sewell having previously served a sentence for a £37,000 wages snatch.

He said: “What was interesting was both Haynes and Sewell were known to have lots of links in Essex and were known to have links on Sheppey as well.

“He was on the run for 45 days, so there were reports that he was on the Isle of Sheppey, hiding down there.

"That is why police searched there.

“The Isle of Sheppey, although it is a lovely place, is not a place where too many people go to, if you don’t know it.

“That is another reason why police thought, with the pair's links down there, that it would be a good place for them to hide, and you have the sea and the beach there as well.”

But the police left empty-handed, heading up to south London in their pursuit.

Haynes was captured first as he watched his daughter compete at the National Pony Championships in Stoneleigh Abbey, Warwickshire. Sewell would remain at large for nearly seven weeks before being nabbed on October 7, allegedly caught relaxing in a bed in Holloway, London.

Sewell was to serve 30 years, eventually being released in 2001, aged 68. In total, the gang of robbers got 93 years behind bars.

But the incredible story was not over.

"I got a lot of behind-the-curtains information..."

Just a year into his lengthy sentence at Gartree Prison in Leicestershire – and barely a week before Maureen Richardson was to posthumously collect the George Cross for her husband’s sacrifice – Sewell with the diversion of a riot, nearly escaped.

He was stopped at the fence by dog handler Joseph Loney Snr, who thwarted what would have been a major incident.

Author Mr Gillen, from Buckinghamshire, a former armed robber himself, said that he spent six months researching for the book in total before writing it inside two-and-a-half months.

He said: “I got a lot of behind-the-curtains information from Joseph Loney Snr’s son. He sent me so many photos and told me about that night at Gartree.

“He remembers the effect Fredrick Sewell had on his father’s life and his family’s life.

“We even spoke to PC Carl Walker’s son - Carl Walker was one of the ones that was shot during the robbery.

“What you have got is an unbelievable story of these men - Gerald Richardson, Joseph Loney Snr and Fredrick Sewell - who are all the same age whose lives were always joined by these events.”

Mr Gillen says Joseph Loney Snr has since died but he believes Sewell remains alive today.

Despite spending most of his adult life in prison, Sewell reportedly had managed to amass around £1 million from property deals behind bars by the time he was released.

Mr Gillen added he is in negotiations with several major publishing houses regarding his new book. It is expected to be released early next year.

For more details about Mr Gillen's career, click here.

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