What happened after the attack revealed nastiness that, in its casual way, was almost as bad. A drive to an Upper Hutt service station, where they cleaned blood off their shoes and ate pies.
On then to Wellington, and a lap around its nightclub circuit before stopping at the Taita cemetery, where one of the killers, who lived in the Hutt, visited the grave of his baby daughter and partner.
They had died two years earlier, on the same date, in a car crash. He had observed the anniversary by killing a man.
When you have no moral compass you just do what you do.
Together again the next afternoon, with news of the killing on the news, the four young, soon to be convicted killers (their ages ranged from 23 to 29) were idly doing "burnouts" in Masterton. Catching them was a doddle.
All of the four are parents. All of them, based on that night's events, are hardly fit to be.
On a brief court appearance last year, Kristofer "Lipsy" Lee Jones, the man who visited the cemetery, repeatedly pulled the finger, mouthed words and grinned at a police officer. What are you supposed to think?
Equally unfit to be a parent was the stepfather of 6-year-old Coral Burrows, who he killed in Featherston in 2003 after a night smoking P, his fifth night and day without sleeping.
He, too, washed the blood off at a service station.
An unemployed farm labourer with 90 convictions, he was by no means anyone's ideal stepfather, yet he was in that position of trust, and this is what he did with it.
All of these details are banal, as someone once said evil is.
It's a series of choices, the kind you make when you think ahead only as far as the next five minutes, and can't visualise consequences.
I make no excuses. There aren't any. But I suspect the small towns of this country, like Featherston, have gone bad since the infrastructure that once surrounded them collapsed.
With that went opportunities for work, which offers the ability to live decently, if modestly, that welfare does not. You can see how hopelessness sets in, especially if you're unskilled. When the world doesn't value you how can you value anyone, even your own kids?
Money isn't a good measure of value, but it has replaced the folk Christianity that knitted small communities together back when those attractive old buildings went up with so much misplaced confidence in the future.
How can we not agree with Carterton district councillor Jill Greathead, chairwoman of the Wairarapa Psychoactive Substances Working Party, in her protest at having to "provide a location" for the selling of legal highs?
Synthetic cannabis has already caused widespread damage in Wairarapa, she said last week; it is a psychoactive substance that eventually leads to psychosis.
"We say that's bad," said Greathead, "yet the Government's telling me this [synthetic] stuff's OK?"
I'm not fooled either. Drugs and idleness are a lethal combination.
Rosemary McLeod is a journalist and author.
