Published Tuesday, 25 February 2014
Sam Marshall was murdered in Co Armagh in 1990. (© Pacemaker)
He was with former republican prisoner Sam Marshall, 31, as he was gunned down after leaving the town's RUC station on 7 March 1990.
On Tuesday, a preliminary hearing of an inquest into his death was held in Belfast.
Eight undercover soldiers were deployed nearby at the time of the killing, but an independent investigation found no evidence of state collusion.
Peter Corrigan, solicitor for Mr Duffy and Tony McCaughey, told the coroner's court his clients should have access to documents disclosed by the security forces.
"The state, we would say, is playing an active part in colluding to murder them in the same incident, 50 shots," Mr Corrigan added.
"They are not witnesses, they are victims, innocent victims."
An investigation by the Historical Enquiries Team (HET) of detectives found no evidence of collusion with the suspected Ulster Volunteer Force (UVF) gunmen and said police officers or soldiers had no prior knowledge of the attack.
It said undercover soldiers were deployed near the scene while their commander monitored events from a remote location.
The armed troops were in six cars, including a red Maestro.
Two plain-clothed soldiers with camera equipment were in an observation post at the entrance to the police station as the three republicans, Mr Duffy, Mr Marshall and the dead man's brother-in-law Mr McCaughey, arrived at the barracks as part of bail arrangements related to legal proceedings.
Two soldiers followed them on foot as they left and partially witnessed the shooting.
The killers' two guns were never recovered - but were linked through ballistic tests to three other murders and an attempted murder.
Mr Corrigan argued that his clients should be accorded full legal standing during the inquest and given access to documents.
He said they were the subjects of attempted murder bids and this was relevant to the inquest's deliberations on whether security forces colluded in Mr Marshall's murder.
"So they have certainly an interest in these matters, they were part of the issues in relation to the surveillance when the matters took place, they were shot at themselves," he added.
"They are certainly interested parties and on that basis we would request that they obtain the same disclosure."
Non-sensitive material is due to be disclosed to coroner Suzanne Anderson's office within weeks but the barrister for the Ministry of Defence and Police Service of Northern Ireland, Mark Robinson, said he would be contesting any application to give the other two men full status and their lawyers access to papers.
"At this stage they are simply only witnesses and therefore disclosure should only be to the properly interested parties," he added.
© UTV News