In the early 1990s, following the murder of
Loughlin Maginn,
John Stevens was named to investigate allegations of collusion between loyalist paramilitaries and the
Royal Ulster Constabulary (RUC). Stevens was able to use advanced fingerprint technology, then unavailable to the RUC. The Inquiry team uncovered Nelson's fingerprints on some security force documents. The team began an investigation that, despite the
obstructions encountered, would lead to Nelson's arrest. When the
Stevens Inquiry Team arrested and interrogated Nelson, he claimed that he had been acting on behalf of the government. Stevens spoke to John Deverell, head of
MI5 in Belfast, who confirmed that Nelson had worked for Army Intelligence and not the RUC. Sharp disagreements developed between the two security branches as the extent of Nelson's illegal activities within the
Force Research Unit (FRU) was uncovered. Over a period of two months, Nelson dictated a police statement covering 650 pages. He claimed that he had been tasked by his military handlers with transforming the UDA into a more effective force, particularly at killing. Using information that should have been confidential to his handlers, he produced dossiers or "Intelligence Packages" including backgrounds, addresses, photos and movements on proposed targets, which were passed on to UDA assassins. In a 2000 interview with the Sunday Herald, an unnamed FRU operator identified Margaret Walshaw as being Nelson's primary FRU handler between 1986 and 1990, and accused her of colluding with him by sourcing maps, photos, and personal details of people to be targeted for assassination. The article further alleged that Walshaw even bought Nelson a
personal computer so that information could be more effectively passed to him in
floppy disk format, and the chances of him being arrested with incriminating documents could be reduced. ==Trial==