British state 'encouraged killings'
Former Ulster Volunteer Force (UVF) leader Robin Jackson was allowed by state forces to kill with impunity, Sinn Fein have said.
John O'Dowd, the party's Upper Bann MLA, said the now dead loyalist was a known security forces agent and a blind eye was turned to his reign of terror.
"This speaks volumes about the British state's involvement in the conflict and rather than claim, as they did, that they were impartial observers or some sort of peace keeper, they were in fact up to their necks in facilitating and possibly encouraging sectarian killings and much more," he said.
Mr O'Dowd blamed the British Government's reluctance to support an independent international truth commission on the potential fall-out from revelations about agents like Jackson.
Dolores Kelly, SDLP Upper Bann MLA, said the Historical Enquiries Team report on the Miami Showband killings underlined the need for a proper process to deal with the past.
She said: "There has been a long-held belief that there were people in the security forces, including the RUC, who were involved in brutal crimes. This report confirms that and is a vindication of the families' campaign."
Ms Kelly said it also confirmed very serious failures in the RUC's investigation of serious crimes.
"The enormous question about why Robin Jackson was allowed to carry out this terror and inflict so much pain on victims over such a long period of time must be answered by the state as we cannot help but think if he had been put behind bars some people's lives may have been spared," she said.