A man killed on a train in front of his teenage son was stabbed nine times, a court has heard.
Lee Pomeroy, 51, from Guildford, died in the attack on a train near the town on Friday.
Darren Pencille, 35, of no fixed abode, made two separate court appearances on Monday charged with murder and possessing an offensive weapon.
He told Staines magistrates: "Innocent until proven guilty," adding: "I'm paranoid. I'm hearing voices."
He later appeared at Guildford Crown Court, along with Chelsea Mitchell, 27, from Willbury Road in Farnham, who is accused of assisting an offender by helping Mr Pencille leave the scene and change his appearance.
Both were remanded in custody until their next court appearance on 7 February.
During the first hearing, magistrates were told Mr Pomeroy, an IT consultant, suffered nine stab wounds in the attack in front of his 14-year-old son.
Mr Pomeroy, who would have celebrated his 52nd birthday on Saturday, was described by his family as "an honourable man and would always help somebody who was in trouble".
"He was a devoted family man and did everything for his family," they said.
Mr Pomeroy died on the 12:58 GMT train service between Guildford and London Waterloo which he and his son boarded at London Road station on Friday afternoon.