The Unusual Suspect by Ben Machell review – a modern-day Robin Hood?

The homeless man sitting with his dog on a cold December night in Sidmouth must have thought it miraculous when a passing stranger dropped a roll of £20 banknotes in his hat. The stranger didn’t stop or say anything, just walked away. Even odder, every note had been marked with two letters: RH. The stranger wasn’t acting out of Christmas charity but from a sense of righteousness: he saw himself as a 21st-century Robin Hood, duty-bound to rob the rich and give to the poor. To which end, a few hours before, he’d held up the Lloyds TSB bank branch in nearby Seaton and made off with nearly £5,000.

A hard-up geography student at the University of Worcester, Stephen Jackley was the unlikeliest of bank robbers. It’s not just that he wasn’t out for personal gain (though he enjoyed using some of his winnings to travel). He also acted entirely alone, albeit after learning from the methods of illustrious peers such as the American Carl Gugasian, whose example taught him the importance of meticulous planning, physical disguise and how to escape and hide your loot in woodland areas. From his first, botched attempt to rob a bank in Exeter the police had a record of Jackley’s DNA. But because he didn’t graduate to bank robbery through petty thieving, they had no match for it on their files and assumed the culprit must be a foreigner, perhaps part of a criminal gang. Undetected, he continued towards his goal of raising £100,000 for what he called the Organisation, his one-man mission to save the planet from poverty and injustice.

He had grown up fairly poor himself, in a series of small Devon towns, latterly Sidmouth, “a cemetery with streetlights” as his best, indeed only childhood friend Ben Weaver called it. Though, to Jackley there was plenty to like about Sidmouth, not just the surrounding countryside but the Norman Lockyer Observatory, where he developed a passion for astronomy. It was a passion that also planted “a seed of doom” – a fear of global disaster that had him fantasising about underwater cities and colonised stars. Cramming his journal with science, philosophy and poetry, he was a neglected and lonely child, born late to parents who had met while patients on a psychiatric ward. His mother had further psychotic episodes throughout his childhood and sometimes the police would come to remove her – the pleasure he later took from outwitting them had an element of revenge for that. His father was domineering and when he died in 2008 Jackley was seemingly unmoved, though it may be no coincidence that his Robin Hood adventures became increasingly erratic thereafter.

A bigger factor than parental neglect – and one of the strengths of Ben Machell’s compelling book is its patient unearthing of the various motivations for his subject’s behaviour – was the trip Jackley made to Thailand and Cambodia two years earlier, where he saw, for the first time, what real poverty looked like. He learned about Buddhism, too, and later spent time in a Buddhist retreat in France, where he questioned a monk about the ethics of doing wrong for the greater good. It was there that he also had his first serious relationship, with an American woman called Rebecca, to whom he divulged his evolving scheme for “unconventional financial gain”. When she returned to Colorado, she invited him to join her. But in his mind the mission came first and the romance slowly petered out. He was on his own, with no Maid Marian for support.

Another vindication of his scheme came from the crisis in the global economy. The collapse of Lehmann Brothers, the nationalisation of Northern Rock, the baling out of banks while the people they were meant to serve went under: the credit crunch of late 2007 and early 2008 showed how corrupt the system was. The shrinking resources of the planet were part of the same problem, he thought: with eco-apocalypse looming, his mission became all the more urgent. That a 20-year-old could save the world by robbing banks and betting shops was absurd. But the absurdity didn’t occur to him. He saw it as his duty.

Most of his robberies were botched. Perhaps the most farcical was when he broke into the office above an HSBC branch in Worcester: finding his way down barred by a metal door, he trashed the place in anger, only to discover the office belonged not to the bank but to the NSPCC. He pledged to repay the charity £25,000 in atonement and did send them a couple of envelopes, one containing £650, with the promise of more to come. But his heists fell far short of the target.

The end to his spree was banal. He had become obsessed with acquiring a gun – if the people he’d held up weren’t scared enough to hand over their money, he reasoned, they must have twigged that the pistol he carried was a toy. Scammed while trying to buy a gun in Birmingham, and arrested while smuggling another through customs in Istanbul, he flew to Vermont, allegedly the easiest state in the US to get yourself a firearm. But the ex-cop working at the gun store spotted his fake ID. And after driving off in a panic, he was arrested. Even then his crimes back in Devon might never have come to light but for the journal he’d brought with him in the car, which detailed both his grandiose long-term plans and his achievements to date.

In the journal he sometimes spoke of himself as a “we”, a trait (so Machell reports) that’s common to people with Asperger’s. That Jackley was on the spectrum is something readers will quickly infer but which Machell delays discussing – aptly so, since it wasn’t put forward as a defence at his trial and was only diagnosed halfway through his 13-year jail sentence. An earlier diagnosis might have helped his education and made him feel less of a loner. It would also have spared him the sometimes brutal treatment he received in US correctional facilities, where thanks to that “we” in his journal he was suspected of being part of a terrorist cell.

Collaborations between journalists and criminals often end badly, with the former either being duped by the latter (as Norman Mailer was by Jack Henry Abbott) or “gaining their trust and betraying them without remorse” (Janet Malcolm’s description of Joe McGinniss’s treatment of the murderer Jeffrey MacDonald in his book Fatal Vision). Machell’s book is an honourable exception. He has had considerable help from his subject (referred to throughout as Stephen) without surrendering editorial freedom or fully buying into his version of events. Drawing heavily on Jackley’s journals and diligently tracking down people who met him at different points of his life, the book explains but doesn’t exonerate. The string of robberies left innocent victims traumatised, something Jackley, devoid of empathy, couldn’t see at the time and now deeply regrets.

Released from prison on probation in 2015, Jackley is a contradictory figure: on the one hand an oddball outlaw who acted foolishly, on the other a youthful idealist whose battle against poverty, injustice and the climate crisis many others in his generation are fighting too. This splendid book – less true crime than biography – does full justice to his complexity.

• The Unusual Suspect: How to Rob a Bank and (Nearly) Get Away With It is published by Canongate (RRP £16.99). To order a copy go to guardianbookshop.com. Delivery charges may apply.