Wellington police have apologised for failing to follow up on an assault on a man that left him with broken teeth.
Roger Whioke, 19, from Wainuiomata was punched twice in the face in an apartment building stairwell by another man during an attack captured on security video in October last year.
Police have conceded that they took action only after the victim's mother, Andrea Janes, obtained the video footage and made a complaint to the Independent Police Conduct Authority.
Wellington District communications manager Nick Bohm says Constable Richard Briscoe, one of two officers who attended the incident, has been held to account.
"What the office has acknowledged is that he should have followed up with the victim in this case the next day. That didn't happen and during a conversation the office has had with the mother, he's fell short of our usual standards and he's personally apologised for that."
Mr Bohm says Ms Janes contacted the building's manager and secured the CCTV footage. He says when the officers investigating the incident viewed the film, they could see an assault had taken place and charges would have been appropriate.
Mr Bohm says the constable has written a letter to Ms Janes, saying he was "ashamed".
"The letter says I apologise for not listening to you when you contacted me about your son. I admire and respect your assistance. I will apply the lessons I have learnt from this incident in the future."
A police spokesperson says Constable Briscoe has received extra training.
A 19-year-old man appeared in Wellington District Court on Friday charged with assault with intent to injure. He will reappear on 14 March.
Mother questions if apology genuine
Andrea Janes says she spent three days collecting evidence to give to police because they refused to investigate the attack.
Ms Janes says when she rang police the day after the assault, she was told by a constable she was an over-anxious mother and that her son had initiated the confrontation.
She says she sent police an email pleading for an investigation, but that fell on deaf ears. She then obtained the video footage of the attack and gathered evidence via social media and networking before making a complaint to the IPCA.
Ms Janes questions how genuine the apology from Constable Briscoe is, saying she believes the letter has only been written because she asked for it.
She says she is pleased police have acknowledged their failures, but is not ruling out making a compensation claim.