The Police Ombudsman is to probe the killing of the IRA’s Downpatrick commander during a mortar attack on the RUC in 1991.
Relatives of Colum Marks ended their High Court challenge yesterday after learning the Ombudsman is to launch an investigation amid claims of a shoot-to-kill policy.
Barrister Sean Devine said the move follows the emergence of a new eye-witness.
Marks, 29, was fatally wounded when police opened fire during an attempted mortar attack on Downpatrick police station in Co Down in April 1991.
His family and legal representatives claimed the RUC was aware of the IRA operation more than eight hours before the shooting and should have been able to arrest him.
Legal action was taken to compel the Ombudsman to investigate the shooting.
At a previous hearing counsel for the family claimed there was material to suggest a state agent was involved.
They were seeking to judicially review regulations governing the watchdog which prevent it from probing a case where there has already been a police investigation.
But in court yesterday Mr Devine confirmed the challenge was no longer necessary due to the Ombudsman’s decision to investigate.
He added that fresh evidence from a new eye-witness represented a significant development. On that basis the judge agreed to end the proceedings.
The police said Marks ignored warnings to stop and was shot because they feared he posed a threat to them.
But lawyers for his family say an eye witness has come forward who believes they saw Marks being escorted along under police guard after being arrested.
The IRA described Marks as its commanding officers in the Downpatrick area.