Karadi (left), while living as Dragan Dabic. Photograph: STR/AFP/Getty Images
As his confidence in the disguise grew, he became ever more daring. He emerged as something of a star on the Serbian alternative medicine circuit, publishing a regular column in Healthy Living magazine, and securing a franchise to represent a US vitamin company in the region. He also started visiting his local bar, the Luda Kuca (Madhouse), a smoke-filled, rough-edged place that appealed to a shifting crowd of impoverished war veterans, Bosnian Serbs and Montenegrins. It served country wine, ljivovica (plum brandy), and pungent, undiluted nationalism. On the wood-panelled walls were pictures of the Serb modern nationalist pantheon, with pride of place reserved for Radovan Karadi.
On at least one occasion he was persuaded to pick up a gusle, the single-stringed fiddle of the region, and perform an epic Serb ballad under a framed portrait of himself at the height of his power. Yet no one recognised him.
In the end, this epic feat of hiding in plain sight was brought crashing down by a slip by Karadis businessman brother, Luka. Late one night in the spring of 2008, he called Dabic with a phone using an old Sim card that the war-crimes investigators had on their records as being associated with the Karadi support network, and had passed on to the Serbian intelligence services (BIA).
In May, an investigator was dispatched to check on the recipient of the call, this strange Gandalf-like figure in New Belgrade, and the penny dropped. The investigator and his colleagues then had to ask themselves what to do next. Like the rest of the Serbia, BIA was in transition. There was a pro-western reformer in the presidency, Boris Tadi, but the parliament and many of the key posts, including the top intelligence posts, were still in the hands of nationalists. The investigators gambled their careers and, instead of going to their own bosses, took their suspicions to Tadis office, and kept up their surveillance. But Karadis fate still hung in the balance. It was only when Tadi was able to put together a liberal coalition, three months after May parliamentary elections, that he was able to replace the BIA leadership with his own man.
By this time, Karadi was aware he was being watched. According to his lawyer, Sveta Vujacic, the fugitive began to spot unfamiliar faces in mid-July, brushing past him on the stairwell at his apartment block or at the Luda Kuca. He knew he was encircled, Vujacic recalled.
On the evening of 18 July, the man known as Dragan Dabic left 267 Yuri Gagarin Street in a light-blue T-shirt and a broad-brimmed straw hat pulled low over his face. He was weighed down with baggage: a white plastic bag, a raffia shopping basket and a knapsack, all of which appeared to be full. He walked to a nearby bus stop where he was soon discreetly joined by one of his BIA trackers. They both boarded the number 73 bus bound for Belgrades northwestern suburbs. Dabic sat towards the front. His shadow was several seats back.
When they reached the greenbelt around the Serbian capital, a couple of patrol cars steered in front of the bus and four plainclothes policemen boarded, two in the front and two in the back. They made their way toward the middle, posing as inspectors, showing their badges and asking to see tickets. The old man in the straw hat was reaching into his pocket for his fare when he felt a policemans grip around his arm.
Dr Karadi? the policeman asked. No, its Dragan Dabic, the man protested. No, its Radovan Karadi, the policeman insisted.
Are your superiors aware of what you are doing? the man asked.
Yes, fully, came the reply.
The officer ordered the driver to stop the bus, and the captive was escorted onto the grass shoulder. At 9.30pm on 18 July 2008, the flamboyant fiction that had been Dragan David Dabic evaporated. In his place, the ghost of Radovan Karadi, the former high priest of ethnic cleansing who had haunted the Balkans for a decade, rematerialised on a Belgrade roadside as a flustered old man, his straw hat askew, clutching a white plastic bag to his breast.
Adapted from The Butchers Trail by Julian Borger. To order it for 13.99 (RRP 17.99) go to bookshop.theguardian.com or call 0330 333 6846. Free UK p&p over 10, online orders only. Phone orders min p&p of 1.99.