Detective Inspector Graham Pitkethley, district manager of criminal investigations, said a 12-year-old will also be referred to Youth Aid for unlawful interference with a motor vehicle, while the inquiry continues to establish what has occurred.
"There has been a party in the area with a number of youth attending, and we are seeking anyone to come forward that may have been in the vicinity at the time."
Tributes have started pouring in for Kingi on social media.
"An awesome man taken far far to early RIP Norm, light up the skies with your electrical personality," one person said.
Others have described the incident as "devestating" and heartbreaking, and sent their love and condolences to the Kingi family.
If anyone has any information that they wish to share in relation to the assault or was at the party, they are encouraged to contact Hamilton Central Police on 07 858 6200 and quote Operation Argus or they can call CrimeStoppers anonymously on 0800 555 111.