Bunji Fenton, 27, who was shot in the arm, was taken to hospital in a serious condition and was stabilised by medical staff.
Police said Mr Wanahi was originally from Taranaki but had been living in Papakura for many years.
He had four children, including a newborn baby.
The victim's friend, Lewis Tarei, said he had a young family and was straightening out his life.
"He was all good. Sometimes he got in a bit of trouble. But he's just got a new house. He was trying to keep things together for his family."
Detective Senior Sergeant Rod Honan, of Papakura CIB, said at the time a sawn-off shotgun believed to be the alleged murder weapon had been recovered.