Derrick Bird's smiling face stares out from every newspaper front page and television bulletin.
It is an image that is hard to reconcile with 12 innocent people being gunned down in cold blood along the quiet, sunny lanes of west Cumbria.
Across no fewer than 30 different crime scenes, the police are attempting to make sense of something that is utterly senseless by asking the deceptively simple question: who, exactly, was Derrick Bird?
Before Wednesday's carnage, those who lived and worked alongside the 52-year-old thought they knew the answer.
All believed the man they called "Birdy" was a quiet, though sociable soul whose simple lifestyle in the village of Rowrah was occasionally enlivened by a taste for foreign holidays.
Now the curtains are drawn tightly across the windows of his modest home as police stand guard outside - but the shutters he erected to conceal his inner self have been wrenched wide open.
"It's just unbelievable," says local postmaster Derek Gilpin, who knew Bird for more than 20 years.
"When I heard something was up, I thought: 'Oh no, Birdy must have been shot'. I never would have imagined that the boot could be on the other foot.
"He was quiet, but he'd never let you go by without saying hello and asking how you were. It just doesn't match up at all."
It may be significant that the people who knew Bird, for all their shock and loss, have not yet allowed themselves to think of him as a monster or an animal: his acquaintances will tell you, with a disbelieving shake of the head, what a nice guy he always seemed.
With two grown-up sons and a wide circle of friends, he hardly fitted the stereotype of a loner or oddball.
But reports have begun to suggest a different man: one embittered by family squabbles over money, or over petty disputes with fellow taxi drivers at the Whitehaven rank where he worked.
Det Ch Supt Iain Goulding told a press conference on Thursday that initial indications suggested the killings were a mixture of "grudge and random".
Bird's mother, Mary, is said to be seriously ill and it has been reported that he was involved in a dispute over a will. Solicitor Kevin Commons and Bird's twin brother David were among his victims.
Other accounts have Bird involved in a dispute with other cabbies over fares and claims of queue-jumping at the rank. Taxi driver Darren Rewcastle was one of those gunned down.
But to those who knew him, such concerns barely seemed enough to set him on such a murderous path.
"I used to go for a pint with him on Sunday night," says taxi driver James Healde, 48. "He was quiet, but still sociable, like: always good company, always asking about you.
"If these things were bothering him, he didn't let it show."
Another taxi driver, who asked not to be named, recalls the atmosphere at the rank differently.
"There had been rows," the man says. "Derrick wasn't happy.
"But even then, it's the sort of thing you might imagine coming to blows - not ending up with all these people dead."
If such trivial matters drove Bird to kill, however, he would have plenty in common with Dunblane murderer Thomas Hamilton, an obsessive bearer of grudges and writer of indignant letters.
In a rural community like west Cumbria, virtually no-one would have thought anything amiss in the fact that Bird was licensed to own a shotgun and .22 rifle with telescopic sight - the weapons he used to kill and maim on Wednesday.
Future inquiries by police and media will doubtless uncover more about what drove him, although Det Ch Supt Goulding said "it may not be possible to establish all the answers, because we cannot speak to Derrick Bird".
Ultimately, however, Bird's secrets - and the demons he was pursued by - died alongside him.