PSNI detectives investigating the murder of Garda Detective Adrian Donohue have made a specific appeal for information.
Det Garda Donohoe was shot dead two weeks ago during an armed robbery at a credit union in Co Louth.
Police believe the gang involved travelled in a dark coloured Volkswagen Passat from Dundalk to Fews Forest outside Newtownhamilton, Co Armagh.
The car was abandoned and set on fire.
They want to speak to anyone who saw a dark coloured Volkswagen Passat in the area on the night of 25 January after 9.30pm or who may have seen any other vehicles in the area around this time.
They also want to speak to anyone who observed fire, smoke or burning vehicles in the area.