Anger boiled over among supporters and family of Gene Atkins outside the High Court at Auckland after the man accused of his murder was found not guilty.
As they left court the group attacked waiting photographers.
Earlier Alan Gundry who fired two shots, killing Mr Atkins, 28, a friend who had become increasingly violent at his home, was found not guilty of his murder or manslaughter.
Gundry, 30, shot Mr Atkins at his home in Orewa on January 12. Mr Atkins was looking for his partner Sarah Jane Dean, whom he had been fighting with earlier that night.
Mr Atkins had been drinking heavily and the court had been told that five people had witnessed his aggression at a dinner party that evening which had gone badly wrong.
Outside the court Alan Gundry's father told NZPA he was glad it was all over.
"I don't want to say anything bad about the Atkins family, because they were good friends, but we're just relieved this is all over."
Close Gundry family friend Janine Wii said Alan Gundry's two daughters, Ava, 6 and 18-month-old Amelia had written letters to their father today, which read: "To Daddy on your saddest day, we love you."
"His partner Nicole is shattered.
"It's been tormenting for both families," Ms Wii said.
Defence lawyer Graeme Newell said his client was relieved.
"This matter has been resolved within nine months. They were good friends. There was never going to be a celebration after this result, simply relief.
"Clearly the jury decided it was self-defence, there can't be any doubt about that," Mr Newell said.
Detective Sergeant Andrew Wong did not want to comment on the verdicts, but said the Atkins family were obviously upset with the outcome.
Gundry pleaded not guilty to murder, saying the shots were fired in self-defence.
During the case the defence told the court Gundry feared for his life and took action in a "moment of crisis".
Gundry was legally entitled to defend himself and others and self-defence was a complete defence to murder, Mr Newell told the jury.
Prosecutor Kevin Glubb said Mr Atkins had no time to respond to the threat of Gundry's gun.
The Crown rejected Gundry's argument that he feared for his life and did not believe he was provoked to an extent he was incapable of knowing what he was doing.
The jury deliberated for more than seven and a half hours.