The two men shot at a Lower Hutt address in the early hours of Saturday morning - one fatally - were attending a birthday party at the time.
Police are continuing to investigate the homicide.
Police were called to the George Street, Stokes Valley property shortly after 2am and found two men with firearm-related injuries, they said.
One man was dead at the scene and another had life-threatening injuries.
The injured man remains in hospital, police said, where he underwent surgery yesterday and remains in a critical condition.
"Both men were attending a birthday celebration when the incident took place," Wellington District Police Detective Inspector Haley Ryan said in a statement.
"Investigators are continuing their work piecing together the events that led to this tragic incident and identify those responsible.
"Police can confirm local gang members were also at the birthday celebration."
Police remain at the scene in Stokes Valley.
Police are asking people within the community who have privately owned CCTV or dashcam footage within Stokes Valley and the Eastern Hutt Road area between 1am and 3am that day to make contact.
Anyone with any information that will help is asked to contact police by phone on 105, or online at 105.police.govt.nz using Update Report, referencing file number 231216/6245.
RNZ
