A man has been arrested in connection with the capital murder of Detective Garda Adrian Donohoe in 2013.
He was killed outside a county Louth Credit Union following an armed robbery.
29 year old Aaron Brady of New Road, Crossmaglen, Co Armagh was convicted in August of last year of capital murder, for shooting Detective Garda Donohoe. He was jailed for life in October.
The latest suspect was taken into custody this morning and is being held at Dundalk Garda Station.