Patched gang members also gathered at a church near a property which has been under police investigation throughout the day.
The victim, believed to be a Mongrel Mob member, was fatally shot yesterday morning in the suburb of Castlecliff.
Karl Pearce said he had only planned to demonstrate peacefully and to make a statement.
Parker was unhappy his visit was advertised as a closed motivational session for Māori and Pasifika boys and their fathers.
Parker said he's "really dissapointed" the event is advertised as "a closed motivational session for Māori and Pasifika boys".
The other man involved in the incident at a Himatangi Beach property is speaking to police, and has minor injuries to his hand.