An Eastbourne woman has been charged with trespassing on railway property and possessing a knife in a publc place after she was arrested at Lancing railway station on January 19.
Becky Deniro, 31, unemployed, of Hyde Gardens, was also charged with theft from a shop.
She has been bailed to appear at Worthing Magistrates Court on February 7.
A spokesman for Sussex Police said they responded to a report just after 4pm on Thursday of a suspected shoplifter who had gone onto the track at East Worthing Railway Station.
Officers and railway staff located her on the line and she boarded a train to Lancing where she was arrested on suspicion of shoplifting and trespass on the railway, according to police.
A spokesman for BTP confirmed they were called to the scene following reports of a person threatening to harm themselves and joined officers from Sussex Police.