The trial of two men accused of the murder of PSNI Constable Stephen Carroll has been adjourned until Friday.
40-year-old Brendan McConville, from Tullygally, Co Armagh, and John Paul Wootton, 20, from Collindale in Lurgan, deny murdering the police officer in 2009.
Mr Wootton's mother, Sharon Wootton, is charged with perverting the course of justice.
Belfast Crown Court was told Ms Wootton last night applied to change her solicitor.
Lord Justice Girvan described the development as "entirely regrettable" but agreed to adjourn proceedings until Friday in order to ensure that the right to a fair trial was fully protected.
Constable Carroll, 48, was shot dead in Craigavon while responding to an emergency call on 9 March 2009 - two days after two soldiers were killed at Massereene barracks in Antrim.
He had been sitting in the driver's seat of his patrol car and was nearing the end of a 12-hour shift.
He was the first police officer killed in Northern Ireland since the changeover from the RUC to the PSNI in 2001.
Mr McConville, a former Sinn Féin councillor, and Mr Wootton are also charged with possession of a firearm and ammunition.