Police Scotland is to investigate the alleged destruction of evidence by MI5 officers in Northern Ireland more than 30 years ago.
Teenager Michael Tighe was murdered and Martin McCauley wounded after members of the RUC opened fire in a hayshed in Co Armagh on November 24, 1982.
Claims later emerged that MI5 had listening devices hidden in the building at the time, but the recordings were destroyed.
The bugging operation was discovered by Sir John Stalker, the former Deputy Chief Constable of Greater Manchester Police as part of an investigation into 'shoot to kill' claims. A lawyer representing McCauley argued last year that had the evidence not been destroyed, it could have backed his claim that police issued no warnings before opening fire.
Lord Chief Justice Sir Declan Morgan said getting rid of evidence of the eavesdropping operation arguably amounted to a perversion of the course of justice.
Yesterday, Assistant Chief Constable Mark Hamilton said the Chief Constable had decided that the police investigation should be conducted by an external police service "in the interests of transparency and public confidence".
Police Scotland are now responsible for looking in to MI5 involvement while the Police Ombudsman is to examine the role of the RUC during the attack.
Policing Board member Dolores Kelly said: "This is positive news for the families of the victims. They have a right to know the truth after all this time."