Police say the case surrounding the death of Radio New Zealand journalist Phillip Cottrell was difficult and complex.
A jury in the High Court in Wellington on Monday found Nicho Waipuka, 20, guilty of manslaughter and Manuel Robinson, 18, not guilty.
Mr Cottrell died after being attacked on Boulcott Street in Wellington a year ago.
Detective Senior Sergeant Scott Miller said outside the High Court that the police are disappointed with the outcome.
He said the case was difficult, because there were different experts giving evidence and several witnesses changed their story.
He did not think the verdict will be appealed.
Mr Cottrell's family also said they are disappointed with the verdicts.
Detective Senior Sergeant Miller told Morning Report that families need to look at how young people can get themselves into situations of pure destruction, and what the consequences are.
Listen to more from Detective Senior Sergeant Miller in Morning Report