A woman who used to live in Weston-super-Mare has today (Friday) been found guilty of helping a murderer in the hours after he killed a man on a train bound for London.

Weston Mercury: Police bodycam footage showed Chelsea Mitchell being arrested: Picture: British Transport Police/PA WirePolice bodycam footage showed Chelsea Mitchell being arrested: Picture: British Transport Police/PA Wire

Jobless Darren Pencille, aged 36, launched an 'unrelenting' and 'savage' attack on 51-year-old Lee Pomeroy following a heated argument in front of the victim's 14-year-old son.

Other travellers on the Guildford to London service in January were horrified when Pencille produced a knife and repeatedly stabbed the unarmed man.

The defendant, who declined to give evidence at his Old Bailey trial, admitted having a knife but denied murder, claiming he had acted in self-defence against the 6ft 3in tall victim.

But jurors were told 5ft 10in tall Pencille had a history of violence, having previously stabbed a flatmate in the neck over a minor disagreement in 2010 and had threatened to kill a staff member at a mental health hostel in June last year.

A jury deliberated for 19-and-a-half hours to find Pencille, of no fixed abode, guilty of murder.

His girlfriend, Chelsea Mitchell, aged 28, who after leaving Weston moved to Farnham in Surrey, was found guilty by a majority of 11-1 of helping him evade police after the attack.

Mr Pomeroy had boarded the train at London Road, Guildford, on January 4 for a day out in London with his son.

A heated argument erupted over a snide remark and 'blocking' in the carriage, with Pencille swearing at Mr Pomeroy and calling him a 'pussy'.

Pencille shouted: "You touch me and you see what happens at the next stop."

As Mr Pomeroy remonstrated, Pencille swung the knife and plunged it into his neck, cutting through the jugular vein.

Jake Hallam QC, prosecuting, had told jurors: "Eyewitnesses saw what they thought was the two men trading punches. They were half right.

"They saw Lee Pomeroy punching the first defendant, defending himself, having been stabbed in the neck by him.

"But the first defendant wasn't punching back, he was stabbing. Again, and again, and again."

Pencille got off at the next station, leaving Mr Pomeroy mortally injured with 18 knife wounds to his neck, torso, thigh and arm.

Mitchell picked up the defendant and bought hair clippers and razors for him to change his appearance.

Last month, while Pencille was in jail awaiting his trial, Mitchell sent him a Father's Day card in the name of their stillborn son, in breach of her bail conditions.

In the note, she told him: "I miss you so much, everything is falling apart. Loosing everyone I love and all I want us my family back (sic)."

Jurors were told paranoid schizophrenic Pencille had been seen by psychiatrists since 2004 but had not taken any anti-psychotic medication at the time of the attack.

His mother Ingrid Robertson said: "He always thought people were looking at him or wanted to do something to him."

British Transport Police Detective Chief Inspector Sam Blackburn described Pencille as 'devious and dangerous'.

* Court report supplied by Press Association.