"It's a good name, Feratox," Graham Wright, a scientist who helped Kerr develop it, told the Herald. "But it's a bit of misnomer because the word feral implies something was once tame that has gone wild. Possums were never tame."
As for Kerr, he appears to have gone feral more than a decade ago, when his elaborate hydroponics cannabis operation was busted. Police estimated the 450 plants they found had a processed street value of $150,000.
In November 2014, Kerr mixed highly-concentrated amounts of the poison 1080 with infant milk formula and posted it to Fonterra and to Federated Farmers threatening to release poisoned infant milk powder into the Chinese market and one other unless the country stopped using that possum-control chemical.
Kerr claimed that he'd just "snapped". But that explanation doesn't equate with the circumstances or his form. Rather than an impulsive act, the blackmail took days - typing the threats, mixing the poison with infant formula, making the long drive from Auckland to post the letters in Paraparaumu. Kerr was on bail at the time for selling and possessing for supply "Ecstasy-type pills" that contained the class C-controlled drug Benzylpiperazine (BZP). BZP is a psychoactive substance that has been on the recreational drug scene since around 2000.
Kerr is no scientist and his attitude to safety practises was lax. When police raided his premises on Highbrook Drive, East Tamaki, they found pills were being pressed alongside rat poison he was developing. Powder and more pills were found at his storage unit. All up, warrants uncovered 32,000 pills which could have sold for up to $40, possibly netting Kerr as much as $1,280,000. But he later told officers he had only been flogging the tablets at $2 a pop.
Kerr is to be sentenced on the BZP charges on July 8. He was sentenced in March to 8 years' jail for blackmail.
Kerr tried to claim his blackmail motives were altruistic - the way 1080 was used had become too risky, he claimed - but Chief High Court judge Justice Geoffrey Venning decided that Kerr's motivation was money.
If 1080 was banned, as Kerr demanded, sales of his ground-laid poison would rise at least for some years while another product that can be distributed by air was developed.
Kerr could expect a rise in his income from royalties. The Crown said his bank accounts were at their maximums, he had extended the overdraft of his mother's account in "questionable" circumstances", and he was struggling to pay his bills.
Jeremy is a little inclined to buck the system and ... break the rules.
The judge said it was "near the most serious case of its kind". The Prime Minister said all New Zealanders would be appalled.
Kerr's lawyer, John Billington, QC, told the court that he could not offer "a rational explanation for what is irrational behaviour". A psychologist had found no evidence of Kerr being particularly callous or lacking empathy, he said.
Money, as the judge noted, along with Kerr's personality traits may explain it. "Jeremy is a little inclined to buck the system and doesn't sort of hesitate to break the rules," said Wright.
"He's got this funny attitude that everyone in charge, police officers, inspectors of any description, they're all f***king idiots. He thought they were just silly and why should he obey anybody else's silly rules if he didn't want to."
Wright doesn't excuse Kerr but said that he "is not an evil person".
"I'm disappointed in him. I thought he was a better man than that. It doesn't mean he's not my friend, but I'm embarrassed to be his friend."
Wright and his wife, Colleen, described Kerr as sociable, polite and generous.
"He was fun to be around, jovial. He had a lot of friends. Friday afternoons he'd shout a beer, brown o'clock at the end of the week."
Kerr was in the early stages of developing Feratox when he approached Wright looking for a skilled tabletmaker.
"Once the product was right and registered the idea was to start up a factory."
Wright was offered a job helping to set that up, make the first few batches and launch the product."
Kerr was offering a car and more money. "I didn't take much convincing. Time for a change, time for a new challenge," said Wright.
At the time, Kerr was managing Kerr Honda, in Howick, a car sales, petrol station and workshop rolled into one. He was probably getting a bit bored with the car industry, Wright said. As a young man Kerr shot and skinned possums and developing Feratox began almost as a hobby. The early days were exciting. There was promotional work, trips to Fieldays, nothing to warrant concern.
"We were just legitimately making a new product and ideally going to sweep the market with it."
Feratox is cyanide based and tricky to make as cyanide is hydroscopic.
"If you put a pile of it down here it will absorb moisture from the atmosphere and turn to mush. It has to be encapsulated with a hard coating to seal it. The idea is that the cynanide core stays dry and powdery.
The possum cracks it with its back teeth, cyanide spills throughout its mouth and drops it one the spot."
The disadvantage was users needed a licence for cyanide poisons, restricting sales to the likes of land authorities and licensed farmers.
Kerr had a lot of faith in the product and worked hard. It more than paid its way but wasn't the bonanza he had hoped.
Apart from battling to get Kerr to comply with health and safety rules that forbid food to be consumed in the factory, Wright said Kerr gave him no cause for concern.
That was until 2004 when half a dozen police cars descended on the premises Kerr had rented in Sir William Ave along from the Feratox operation. Kerr had claimed he needed somewhere quieter. Fuel tablets - an additive to enhance fuel economy - were produced from the site but most of the space was taken up by a hydroponics cannabis operation behind a makeshift wall. A forest of mature plants were growing inside shipping containers equipped with extraction fans, ultra-violet lighting and watering systems.
"He had a secret side," said Duncan MacMorran, chief executive of Connovation Ltd which sells Feratox. Kerr was not a shareholder of that company but received royalties. "He could be very personable but there is clearly a different side to him," MacMorran said.
Kerr's second involvement with illicit drugs was the "Ecstasy-type pills" episode. Kerr came on to the police's radar when he was observed meeting one of the main suspects of Operation Ark.
Covert searches in 2011 of Kerr's storage unit and business premises found thousands of pills, buckets of powders, pill dyes with a variety of logos such as are commonly found on Ecstasy tablets, and other paraphernalia for pill pressing, according to a Crown summary of facts. Kerr will be sentenced on those charges next month.
Wright, who left Connovation about a decade ago, said everybody was shocked by the cannabis bust but Kerr seemed to play it down; "Oh, it will blow over".
He could be very personable but there is clearly a different side to him.
The Wrights remained friends with Kerr and supported him after his wife, Wendy, died of cancer a few months before he was charged in connection with the party pill operation.
"I think he did go a little bit off the rails after Wendy died. He was lonely and he was looking for female companionship. He tried online dating," Wright said.
"He was used to living in a big house with a wife and two boys. Suddenly he was living in a big house by himself."
One son moved away to study, the other moved in with his partner.
But three money-driven crimes? He had a good income but never seemed quite satisfied, said Wright.
"I don't know if I would regard him as greedy but he always wanted to be rich and he enjoyed spending money. If you're going to spend it you have got to make it somehow ... " He'd always wanted a boat, holidays, a comfortable life.
After Kerr was charged with blackmail, he rang the Wrights from prison. Remorse, the cost to the country didn't come up in the conversation.
"He did say, 'it's probably the dumbest thing I've done in my life'."
"When he gets out I will invite him around and we will sit on the deck and have a beer," Wright says.
Assets associated with Kerr including a Mellons Bay house, a yacht, two cars and various bank accounts were frozen under the Criminal Proceeds (Recovery) Act.
