Convicted of theft but allowed to own two guns... The family feud that sparked Derrick Bird's rampage (with new video)

Cumbria killings: Full coverage

As emotional tributes were paid to his victims, detectives were piecing together what made the quiet taxi driver launch a massacre in Cumbria yesterday.

Locals suggested Bird might have snapped after a row with his brother over a will or following an argument on Tuesday night in which he accused other cabbies of stealing his passengers.

It emerged today that the 52-year-old divorced father of two was convicted of theft in the 1990s, but was allowed to obtain a shotgun licence in 1995 and a firearms licence for a rifle in 2007.

Critics questioned whether police could have kept the death toll lower by stopping Bird sooner.

Meanwhile, survivors spoke of their terror at coming face-to-face with the cold-eyed gunman as he calmly shot passers-by before driving on.

Bird's trail of killing began when he left his home in the village of Rowrah just before 10am armed with a shotgun and a .22 rifle with telescopic sight.

He is thought to have driven to nearby Lamplugh, where he shot dead his twin brother David.

The gunman continued to Frizington, where he murdered family solicitor and good friend Kevin Commons, 60, on the driveway of his home.

Bird then drove to the town of Whitehaven, where he shot at least three fellow taxi drivers, killing Darren Rewcastle.

A second cabbie, former soldier Don Reed, was shot in the back, but managed to crawl away on his hands and knees.

Bird, a former Sellafield worker who recently became a grandfather, then drove through the picturesque Cumbrian countryside blasting people he encountered along the way.

His other victims were: young estate agent Jamie Clark, rugby league player and farmer Garry Purdham, retired couple Jennifer and James Jackson, part-time mole-catcher Isaac Dixon, shopper Susan Hughes, unmarried pensioner Jane Robinson, former Sellafield worker Kenneth Fishburn and retired Michael Pike.

Another 11 people were wounded, eight of whom remained in hospital today.

Britain's worst mass shooting since the 1996 Dunblane tragedy ended after three hours with the discovery of the gunman's body 20 miles from Whitehaven in woods near the hamlet of Boot.

Home Secretary Theresa May said police had confirmed that Bird's gun licences covered the two weapons seized by officers after yesterday's massacre.

She welcomed debate about Britain's gun laws but said it would be wrong to act until the full facts of the tragedy were known.

"When there are lessons to be learned, we will learn them, and when there are changes to be made, we will make them," she told the Commons.

Mrs May and Prime Minister David Cameron will visit Cumbria tomorrow to meet senior police officers.

Bird knew some of his victims - his twin brother, a solicitor and taxi driver colleagues - but many of them appeared to have been picked at random.

Even though he once worked at Sellafield, the killer had no previous acquaintance with Mr Jackson, who is also believed to have worked at the plant.

A spokeswoman for Sellafield said Bird resigned from his job as a joiner in 1990.

She said there was no record of him ever working with Mr Jackson.

Those who survived encounters with Bird spoke of their lucky escapes today.

A former schoolmate described meeting the taxi driver in his car outside the home of solicitor Mr Commons as she walked her dogs at about 5.30am yesterday.

Shop worker Iris Carruthers, 49, said she recognised him and said hello, but he did not reply.

She said: "He passed me and went down to the bottom of the main road, turned, and he came back up.

"Slowly he drove alongside me and I said 'hiya lad, you all right?'. He didn't speak, he was in a world of his own, and I just kept on walking.

"He was stationed at the gate on the way up to the tip road (to the recycling facility). I just left him there.

"I thought he was just normal, I didn't think there was anything untoward. I just thought he had been to the farm and dropped somebody off because he was in his taxi. I never thought any more of it."

Taxi driver Mr Reed described seeing Bird killing Mr Rewcastle in Whitehaven and then being shot himself.

He told the BBC: "I just took a flying dive and he caught me in the back. I went on the floor and then I crawled along the taxi rank. I was going to apply first aid to Darren, but when I saw Darren, he was gone."

And cyclist Barrie Moss described how he dramatically looked the killer in the face seconds after he had used his rifle to murder Ms Hughes in the town of Egremont.

Mr Moss, 43, said his encounter with Bird was "like something out of a James Bond movie".

He said: "He stared at me, probably not for very long, but seems longer now. He scurried into the car and drove down the hill. It was only when he had driven off that I saw a body slumped on the pavement."

Those who knew Bird - known to friends as "Birdy" - tried to find explanations for his actions today.

A taxi firm owner who used to work with him suggested that the stresses of the job had come to a head with him shooting other taxi drivers he believed had taken custom from him.

He said he understood those shot - including Mr Rewcastle - had been accused by Bird of taking his customers.

All the cab drivers targeted by Bird were his friends and some went on holiday to Thailand with him.

It also emerged that Bird had been left "nervous and anxious" after an attack by one of his taxi passengers three years ago.

Questions were asked today about why police did not stop the killer more quickly.

Among messages of condolence left on the website of local paper the Whitehaven News were angry condemnations of Cumbria Police's handling of the tragedy.

Bob Lunn wrote: "I feel sorry for the people who have died, and the family and friends that they left behind.

"But how was this guy not stopped sooner? I can understand the inevitable two or three people getting shot, but 12 dead?

"The police should have been all over it as soon as there was a reported shooting... The police have a lot to answer for in my opinion."

A Cumbria Police spokeswoman said the force could not comment on the criticism.

The Independent Police Complaints Commission said Cumbria Police would decide whether it needed to refer any matters to the watchdog "in due course".

The Prince of Wales said today he was "utterly horrified" to learn about the shootings.

Last night the Queen said she was "deeply shocked" by the tragedy and shared the nation's "grief and horror".