A MAN who was obsessed with the devil killed his wife and two children because she would not give up smoking.

John Jarvis pleaded guilty to the manslaughter of his wife Patricia, 38, and their sons Stuart, eight years, and John Jarvis Junior, 11 years, on the grounds of diminished responsibility and was today beginning a life sentence.

Jarvis, 42, stabbed his wife and their two children to death at the Winslow Hotel where the family lived in Blackpool last March.

When police arrived, they found him lying in bed next to his dead wife.

A Bible on a table was open at the Book of Revelations, with a cigarette lighter on top.

The couple had married in 1986 when they were living in South Africa but moved to Kent in 2000 after the death of Mrs Jarvis' mother and then to Blackpool where she ran the Winslow Hotel. She had previously lived in Darwen, where her parents were from, and still had relatives in the town.

Sitting at Preston Crown Court, Judge Peter Openshaw QC sentenced Jarvis to life imprisonment in a maximum security hospital.

Iain Goldrein QC, prosecuting, told the court that Jarvis killed his wife telling her he was "going to fix" her smoking habit.

He slashed her throat and stabbed her through the heart "so she couldn't be resuscitated". Their son Stuart entered his parents' bedroom after hearing screaming. Jarvis admitted stabbing Stuart to death so he would not have nightmares about the sight of his father killing his mother.

He then went upstairs to John Junior's room, where he cut his throat, telling him he was going to join his mother.

Jarvis then washed himself and the weapon before stabbing himself.

The court heard that a police officer later heard Jarvis saying: "I tried to stab my heart out but my blade was too blunt."

Jarvis then got back into the bloodstained bed with his dead wife. The QC told the court that Jarvis had once told a friend: "If I have proof that Patricia is smoking I will kill her."

The judge accepted three pleas of manslaughter on the grounds of diminished responsibility after hearing that Jarvis had developed a mental illness following a road crash when he was 19.

But he said Jarvis had not escaped justice and may never be released.

Outside the court, Detective Superintendent Ian Jones, who led the Lancashire Police investigation, described the killings as "an appalling family tragedy".

He said Jarvis was "cold and calculating" throughout the investigation and had shown no remorse.