Superintendent Gerry Curley of Dundalk Garda Station has appealed to the public and possible passengers who would have been driven by Martin Mulligan last night to please come forward.
The 53-year-old, whose body was discovered close to his vehicle in Kilcurry shortly after 3am this morning, began work at 9.30pm last night in his silver Skoda Octavia, registration number 07-LH-5599.
The 53-year-old from Waterview on the Lower Point Road is believed to have been stabbed to death following a violent attack at Carnmore, off the R177 Dundalk to Armagh Road, around 3am.
His body was discovered by a female driver close to his car around 3.15am. A forensic tent set up 30 or 40 metres beyond the car suggests he may have been attacked away from the car or staggered away for help.
Mr Mulligan was pronounced dead at the roadside and his body remains at the scene, which has been preserved for technical examination. His family visited the scene earlier this morning.
Anyone with information is being asked to contact the incident room at Dundalk Garda Station on 042 9388400, the Garda Confidential Line on 1800666111 or any Garda Station.