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".