A 31-year-old suspect taken into custody on Saturday after 45-year-old, Dirk Zwitser, was fatally shot in the head on May 9 in Haarlem.
The man had been alive when he was found by police. He died of his injuries two days later in hospital.
A 31-year-old man without a permanent residence was arrested on Saturday in connection with the crime.
Earlier in the investigation police also took a 22-year-old woman from Haarlem into custody. Her involvement is still being investigated.
Police have been looking into the possibility that the shooter was part of the motorcycle club, the Hardliners, the Telegraaf reported. It has not been officially confirmed that the shooter was a member of the Hardliners.
The shooting took place around 9:30 p.m. on Sunday on the Beeksteeg in eastern Haarlem. Police received report of a mysterious loud bang that was not immediately identified as a gunshot.
Witnesses said they a white Volkswagen Caddy speed off after the bang. The car was later discovered by authorities in Zandvoort.