Rowan Baxter on Wednesday murdered his estranged wife Hannah Clarke, 31, and their three young children by setting fire to Clarke's Kia Sportage as she was leaving on a school run.
Baxter doused the car in petrol and lit a match with Aaliyah, 6, Laianah, 4, and Trey, 3 trapped inside. Clarke managed to escape but died from her injuries in hospital.
The 42-year-old Baxter, who was under a restraining order when he committed the killings and had a history of domestic violence, asked bystanders not to intervene as they attempted to put out the flames, before stabbing and killing himself.
The former rugby union player and Tauranga Boys' College pupil played a pre-season game for the New Zealand Warriors against the Eels in 2005 and represented New Zealand A a year earlier.
In a 2004 newspaper interview, Baxter claimed he had quit rugby union - joining the Mt Albert Lions rugby league side in Auckland - after being repeatedly overlooked for selection by the Bay of Plenty Steamers.
"Word got back to me they [Bay of Plenty] thought I had anger problems,'' Baxter told The Daily Post.
"'I pulled out. I thought blow this, they keep bringing in players from outside the union, it was hard especially coming up through the grades . . . to be treated like that was pretty stink. It's a Bay of Plenty thing."
Baxter was involved in two vicious brawls while playing club rugby for Te Puke in 2002 and 2003. In one he threw punches after running onto the field from the reserves bench.
"That's the way I play, I don't regret it, that's who I am," Baxter said after joing the Lions.
"I'm really enjoying it, especially the confrontational stuff. It's been my best year ever with discipline."