The man shot dead in Dundalk last night has been named locally as Seamus McMahon.
Mr McMahon, 41, lived at Green Acres in Dundalk.
Dissident republican involvement has not been ruled out by gardaí investigating the shooting.
It is believed Mr McMahon had republican connections.
He was visiting a woman in the Saltown area of Dundalk when he was murdered.
Two men, both wearing hoodies, entered the building and pushed their way past a woman before shooting their victim in the bathroom of a ground floor apartment.
The attackers fled the scene on foot, but it is thought there may have been a car waiting for them nearby.
The area remains sealed-off and garda technical experts will spend most of today examining the scene.
A post mortem has been carried out on the body.
Gardaí have appealed for anyone who was in the Saltown area and has any information to contact them at Dundalk Garda Station on 042-9388400.