Ballistic tests on the gun used to kill pensioner Roseann Mallon were carried out by RUC Special Branch officers who might not have been properly qualified, an inquest has heard.
The Czech-bought assault rifle, now linked to 11 other murders and two attempted murders, was first examined at the Weapons and Explosives Research Centre (Werc) – a previously unheard of unit located within the Northern Ireland Forensic Science Laboratory, the court was told.
Judge Mr Justice Weir, who is hearing the long-awaited inquest, said: "This is the first time it has ever come to my attention that there was a forensic system within a forensic system." Ms Mallon (76) was gunned down as she watched television at a house near Dungannon, Co Tyrone, on May 8, 1994.
The spinster, who had been staying with relatives because she felt vulnerable, was unable to escape when two loyalist gunmen opened fire.
The UVF said its Mid Ulster brigade had been responsible and was targeting two of her nephews.
The inquest has been adjourned until next May to allow the HET to complete its investigation into 24 murders in the east Tyrone area between 1988 and 1994 – including Ms Mallon's death.