A jury has been shown footage showing the moment a father was stabbed to death on a train in a “quick and frenzied attack”.
The Old Bailey heard Lee Pomeroy, 51, suffered 18 knife wounds in an assault lasting little more than 25 seconds.
CCTV footage showed Mr Pomeroy being repeatedly stabbed on a Guildford-to-London train on 4 January.
Darren Pencille, 36, of Wilbury Road in Farnham, denies murdering Mr Pomeroy but admits possessing a bladed article.
His barrister told the court Mr Pencille did not deny stabbing him but would be arguing that he was acting in self-defence.
The defendant’s girlfriend, Chelsea Mitchell, 27, of the same address, denies assisting an offender.
Jurors watched in silence as they viewed the footage showing the moment Mr Pomeroy was first stabbed.
It showed him and his 14-year-old son buying tickets at the station and then boarding the train at London Road at the same time as Mr Pencille.
It showed the two men arguing before Mr Pomeroy followed Mr Pencille into another carriage, while his son remained where he was.
The footage then showed Mr Pomeroy being repeatedly stabbed while trying to defend himself with his hands.
Det Con Marc Farmer, from British Transport Police, who was responsible for locating and viewing CCTV in the investigation, told the court: “We see the first blow (that was to his neck), and then movement and we see him slash at his torso and then his thigh.
“It is quick and a frenzied attack.”
Justin Rouse QC, defending, asked Det Con Farmer to confirm there was no audio of the apparent verbal exchange, which the officer did.
The barrister said Mr Pencille walked away and was followed by Mr Pomeroy – which the police officer confirmed.
“At the end of the carriageway is a dead end,” Mr Rouse continued. “He can’t get out.”
Mr Rouse added: “The train is in motion and he can’t get out of the doors. Before he turns to violence he resorts to using his phone.”
Det Con Farmer replied: “Yes.”
Mr Rouse then said: “After the blows have been exchanged – and there is no dispute Mr Pencille stabbed Mr Pomeroy – Mr Pomeroy then for the first time retreated, and it’s fair to say Mr Pencille doesn’t take a single step towards him.”
Det Con Farmer replied: “Only to pick up his glasses.”
The trial continues.