The ACT Government has appointed Anthony Whealy QC as an acting judge to preside over former public servant David Harold Eastman's murder case retrial.

Justice Whealy has previously served as a NSW Supreme Court judge and a judge of the NSW Court of Appeal.

Mr Eastman served almost 20 years of a life sentence in jail for shooting dead Australian Federal Police assistant commissioner Colin Winchester outside his Canberra home in 1989.

But in August, the murder conviction was quashed when an inquiry discredited key forensic evidence and found Mr Eastman did not receive a fair trial.

Earlier this month the Director of Public Prosecutions (DPP) confirmed it would retry Mr Eastman for the murder in the ACT Supreme Court.

Mr Eastman's lawyers said they would bring on a stay application to prevent any new trial, but a date could not be set until a judge was found who did not have a conflict with the case.

Attorney-General Simon Corbell appointed Justice Whealy to the position.

"Justice Whealy is a highly qualified suitable acting judge to hear upcoming proceedings regarding the Eastman matter," he said.

"Justice Whealy's skills and experience are exemplary and he will be an important addition to the ACT's judiciary."

Mr Eastman's stay application is expected to be heard next year.