The shooting took place in a room at the Holms cafeteria and motel complex just off the E18 motorway between Larvik and Sandefjord, local newspaper Østlands-Posten reports.
The victim managed to leave the room before falling to the ground at a nearby petrol station.
Police received a report at 3.25am of several shots being fired. A woman who witnessed the events that led to the shooting provided police with information that led to the three arrests.
Police would not confirm a report in newspaper Aftenposten suggesting the victim was shot twice, most likely in the back.
Two men were arrested at around 4.30am, both of whom have criminal records. They were accompanied by a woman, who was arrested and charged.
The victim also had a history of crime.
Newspaper VG said the shooting bore the hallmarks of an underworld killing.