A deadly aggression against a 51-year-old man in front of his 14-year-old son in a train on the outskirts of London. British police arrested the suspect.
Friday afternoon, the man was killed in a train from Guildford to London Waterloo.
Chief Inspector Sam Blackburn said the attack was "not a random attack". He added that the two men were apparently involved in an argument that intensified in the moments leading up to the murder.
The suspect was arrested early Saturday for suspicion of murder. A 27-year-old woman, suspected of helping to kill her, was arrested.
Nobody was wanted for the murder, the police said.