British Transport Police
Bethan Roper, 28, was returning from a Christmas shopping trip with friends.
Network Rail and British Transport Police are urging passengers to take care this festive season, in light of new figures on alcohol-fuelled incidents.
Police say passenger died after suffering serious head injuries.
The attack took place at 9.45pm on Friday.
Police want to trace a passenger captured on CCTV.
'This person pulled a hammer out and just started hitting him.'
A 55-year-old man is in custody.
Pictures posted online showed a blood-soaked newspaper lying on the floor.
Police launch appeal to find man caught on camera.
Officers have released CCTV images of a man.