A man has been charged with murdering "devoted family man" Lee Pomeroy in an attack on a train.
Darren Shane Pencille (35) will appear in court today accused of attacking the father as he travelled between Guildford and London with his son, British Transport Police said.
He was also charged with possessing an offensive weapon, while 27-year-old Chelsea Mitchell was charged yesterday with assisting an offender.
The pair, whose address was given as Willbury Road, Farnham, will appear at Staines Magistrates Court.
Mr Pomeroy, who lived in Guildford and owned an IT firm, was travelling with his 14-year-old son on Friday afternoon when he was attacked.
A police manhunt led officers to a flat in Willbury Road on Saturday morning and they made two arrests.
The 51-year-old father, who would have celebrated his birthday on Saturday, was described by his family as "an honourable man" and someone who "would always help somebody who was in trouble".
In a statement, the family portrayed him as a cultured man who loved his 50-year-old wife Svetlana.
"Lee took his son on a trip to London hoping to spend some quality time with him which was cut short by an horrific and pointless attack," they said.
"Lee would have had his birthday today but did not get to see his presents. He was an honest, bright person, who loved music very much. He knew history and art and he was a bachelor of science in maths.
"He was a devoted family man and did everything for his family.
"He was a loving husband and father. He will be deeply missed by all his family." Mr Pomeroy and his son boarded the 12.58pm train service between Guildford and London Waterloo at London Road station on Friday.
Police believe a brief row broke out, leading to Mr Pomeroy's death.
Mr Pomeroy and his suspected killer appeared to become involved in a three to four-minute row moving through the carriage and into another before it escalated into violence, police said.
The other man fled the train at Clandon station while the service continued to Horsley station where police and paramedics attended.
At 6am on Saturday a suspect was arrested at a flat near Farnham Hospital on suspicion of murder, alongside a woman who was detained on suspicion of assisting an offender. Both suspects will appear in court today.
British Transport Police said yesterday: "A man has today been charged with the murder of Lee Pomeroy (51) following an investigation at Horsley station, Surrey.
"Darren Shane Pencille (35), of Willbury Road, Farnham, has been charged with murder and possession of an offensive weapon in connection to a fatal incident on board a train from Guildford to London on January 4.
"He has been remanded in custody and will appear at Staines Magistrates Court tomorrow.
"Chelsea Mitchell (27), of Willbury Road, Farnham, has also been charged with assisting an offender.
"She has been remanded in custody and will appear at Staines Magistrates Court tomorrow."
Police are not looking for anyone else in connection with the killing of Mr Pomeroy.