Everyone who knew Derrick Bird described him as a quiet, unassuming man.

To his neighbours in the Cumbrian village of Rowrah, the 52-year-old grandfather was just the "normal bloke" who lived down the road.

But as more details emerge of the terrible killings, attention is turning to what sparked it, with reports of a bitter family feud that may lie at the heart of it.

It is believed his first victim was twin brother David and reports suggest the pair had clashed over a will.

Police have confirmed one of Mr Bird's victims was solicitor Kevin Commons, who was believed to work for the family.

In his home village, locals painted a picture of a quiet man often seen enjoying a pint and a chat in the Hound Inn in nearby Frizington.

No one appeared to have had the slightest inkling that Mr Bird, a divorcee who lived alone, possessed the capacity to kill.

With short receding hair and a heavy physique, pictures released of the middle-aged man appear to show a relaxed figure.

Ryan Dempsey, 26, who lived two doors down from the killer, said: "I have known him for 15 years. He was always pleasant, always had time to say hello.

"He was often on the roadside fixing his car. I knew his job was a taxi driver and I think he loved his car, he was always tinkering with it." Mr Dempsey said he had never seen Mr Bird carrying a gun or a shotgun, but he added that, in that part of the countryside, game shooting is not uncommon.

He said: "As far as I'm concerned, this is completely out of character. I had never seen him in a bad mood."

Glenda Pears, who runs L&G Taxis, described him as a "real nice man".

Mr Bird had two grown-up sons, one of whom became a father for the first time two weeks ago.

It is believed his ex-wife lives in the nearby village of Lamplugh, home also to one of his two brothers, local residents said.

Michelle Haigh, landlady at the Hound Inn in Frizington, was shocked to find that one of her regulars was responsible for the rampage that left 12 dead.

He would often stop off at the pub, which is about three-quarters of a mile from his home.

Ms Haigh said: "He was just a normal bloke. He was a nice guy, nothing out of the ordinary. He would come into the pub, have a couple of pints, have a chat with his friend and go home.

"This is not in character with the Derrick Bird we know."

She added: "He was just a nice guy. Everybody is shocked."

The 41-year-old landlady said no one she had spoken to could think of any trigger for the change in his behaviour.

The Rev. John Bannister, rector of Whitehaven, said he did not know Mr Bird but had spoken to those who did - and yesterday's events had shocked them.

"I have spoken to people that did know him and no one has said anything about him that would indicate that he was capable of this kind of behaviour," he said from the scene of one of the shootings in Duke Street, Whitehaven.

"He has no history. He has lived a quiet life. It has come totally out of the blue, really."

It emerged that Mr Bird, who held a firearms licence for 20 years, had been left "nervous and anxious" after an attack by one of his taxi passengers three years ago.

He was knocked unconscious in a row over an unpaid fare in October 2007 and no longer wanted to work nights after the assault.

According to a report from the Whitehaven News, Mr Bird picked four people up from Tangier Street in Whitehaven after a night out. But at the end of the journey, the group refused to pay, and a 19-year-old man hit him on the back of the head, knocking out two of his teeth, one of which was false.

Whitehaven magistrates heard that Mr Bird woke up to find himself injured and could not remember being attacked.

In a statement to the court during a hearing in April 2008, he said he was "nervous and anxious" as a result of the assault.