They say the 15-year-old Kelston Boys High pupil knew he was to fight another boy and he was fearless despite being small.
His main opponent, whom the Weekend Herald cannot name for legal reasons, was allegedly helped by an older teenager, but the police say the pair did not act with murderous intent and are not likely to face murder charges.
Police say they threw the fatal punches in a "moment of madness and they'll have to live with the consequences" for the rest of their lives.
Stephen died in hospital on Wednesday Day night from injuries he received in the fight after training for a junior team had finished.
He wasn't known to his family as a fighter but as "gentle, well mannered and respectful", his aunt Margaret Dudley said.
"But apparently it was pre-arranged, like they do ... You know, there will be a fight after school ... so I've heard that was the situation."
If that was true it came out of the blue to the family.
"There is a culture in these schools that fighting is to be expected and is the norm ... It's part of a culture to have these organised fights after school," Dr Dudley said.
Fighting didn't fit the nature of the Stephen they knew, she said.
"I think he was a little bit fearless, he was quite a slight boy ... He was never a big rough kind of guy and that could have been his undoing, I don't know."
Dr Dudley said family members were gathering to support Stephen's parents Brent and Mona.
Her daughter Rachael Andrew said the phone call they received from Stephen's father to break the news was "haunting".
"He said to my Mum that he was beaten to a pulp. It was a school yard fight that got out of control. I could hear his mother in the background and it was haunting the way she sounded. It was her eldest son, he was precious."
Ms Andrews said one of Stephen's cousins lived with her and also attended Kelston Boys.
"He was just talking to Stephen after school and they were going to walk home together but Stephen stayed for rugby. By the time [my nephew] got home and walked through the gate I already knew and told him, he couldn't understand, he said 'but I just saw him'.
"I will be picking him up and dropping him off every day now."
She said the family were "devastated"by the tragedy.
""He was really good to his mother, he helped her a lot because they had young kids - he didn't mind doing the chores around the house. Most teenagers hate doing that sort of thing but he would always help."
Two boys, one aged 15 and the other 17, have been charged with assault and appeared in court in Waitakere yesterday.
Judge Brian Callahan suppressed all details that would identify them. The 15-year-old was subject to a blanket suppression order preventing the media from reporting anything but the fact that he had appeared in court.
The 17-year-old was remanded on bail as his parents, aunt and cousins looked on from the public gallery.
The accuseds' lawyer, John Munro, said the youths would be taking time to collect their thoughts on what had happened.
"[They] are very upset for everything , they're just upset all round and they are taking some time to settle down and reflect on things," he said.
It's understood the fight was supposed to be one-on-one but the second boy joined in and together they punched him until he fell to the ground.
A witness told TV3: "There was just a bunch of boys having some fights up there ... I came back and he was on the ground, gone. So me and my mate gave him CPR. It was too late."
Detective Inspector Bruce Scott said a pathologist had completed a physical examination of Stephen's body but was still doing some toxicology work.
He said he could not make any comment about the results of the post-mortem examination. Based on the evidence presented to police thus far, neither of the accused teenagers would be charged with murder.
"There's certain intents that you have to prove for a charge of murder and I don't believe in the circumstances as we know them at the moment that we would have those intents, or be able to prove those intents to the court."
It seemed like "a moment of madness, and they'll have to live with the consequences".
Police had received an "indication"from someone that a witness had filmed the assault on their cellphones, so the phones of several people had been taken for examination.
"We've taken the cellphones with their permission to see what's in them. All the students police had spoken to were co-operative, he said.
"They're all good kids."
He did not rule laying further charges against the two teenagers arrested and depending on the results of a post-mortem examination "other charges may be preferred".
Stephen's body was released to the family late yesterday afternoon. His funeral service will be held at Kelston Intermediate School on Tuesday, where his father is a caretaker, before his burial in Waikumete Cemetery.
- Andrew Koubaridis of the New Zealand Herald and Matthew Theunissen of APNZ/additional reporting: Morgan Tait and Edward Gay
