"Police managed to get him under control and took him back to the Whangarei Station. He is facing charges of assault with intent to injure and assaulting police."
Mr Metcalfe said this was the second time in a week where police had to deal with someone under the influence of psychoactive substances after officers found an 11-year-old boy in a very disoriented state on Maunu Rd last week. They took him to Whangarei Hospital to detox.
Dr Reti, who is the National Party candidate for Whangarei in September's general election, said he was disappointed by the level of violence he witnessed just after 9pm on Wednesday that involved two young men "kicking the heck out of" a boy on the ground in Rathbone St.
He captured part of the assault on video when he left his camera running after filming a video for his Facebook page at the Field of Remembrance in Laurie Hall Park.
Watch: Raw: Whangarei GP rescues assault victim
While driving out of Laurie Hall Lane on to Bank St, he noticed a car stopped in the middle of the road and heard a commotion before realising what was going on - a boy aged 15 or 16 was curled up in the foetal position while two young men took turns kicking him. Dr Reti got out of his car and approached the attackers who stopped the assault.
"The young man was bruised and dazed but conscious and I applied the required medical cares until the police arrived," he said.
Police are carrying out further inquiries to identify the offenders and would like anyone with information or who may have witnessed the attack to come forward.
Dr Reti said the community must unite and work with police, Whangarei District Council and other agencies to stop the city getting a reputation as a violent place.
"Helping the police to keep our city safe is a personal and a community responsibility. Assaults in public places in the Northland district have decreased to year end 2013, but we can still do more," he said.
"The City Safe programme is a very successful and visible programme in the city. [As well, WDC] is developing the concept of a 'night-time economy' for the central city which will have businesses opening later hours, and more foot traffic enjoying the central city at later hours, thus decreasing night-time crime."
Dr Reti, who has served in the army, said it was ironic that the purpose of the night-time film shoot was to encourage people to attend the Anzac Day service and to acknowledge what those who died fought for.
"The brave soldiers at the Field of Remembrance only had to turn their heads last night to observe what was happening. I hope in my heart that they saw at least something in the evening air that validated their sacrifice and gave them hope also," he said.