Teenage girl died from single stab wound to chest on Birmingham bus Det Supt Richard Baker from West Midlands CID said: "We know there are a number of passengers who were on the bus yesterday morning when Christina was attacked while she was sitting upstairs. Some of these passengers were sitting downstairs on the bus and they haven't yet spoken to police. They may not even have known what happened but may have vital evidence and it is crucial they contact us as soon as possible on 101. Miss Edkins's half brother Ryan Harris, 18, posted a photograph of his sister on Twitter this morning, alongside the message: "Would do anything to see you! I love you. A 22 year-old man, named locally as Phillip Simelane, remains in custody. He was arrested yesterday on suspicion of murder after being spotted acting suspiciously behind a Morrisons supermarket, just a few hundred yards from the scene of the attack. Mr Simelane lives with his mother around two miles from the scene in a run-down terrace in the suburb of Smethwick. The attack came just weeks after Miss Edkins published a series of messages online in which she expressed concerns about a man who was behaving oddly on the bus. She wrote on Twitter on February 8: "This man is worrying me on the bus, keeps getting up and walking up and down stairs and sitting in different places." The teenager, who had ambitions to become a nurse, said she could not wait to be old enough to take driving lessons as she "hated" the method public transport. A family friend disclosed that her parents, Jason Edkins and Kathleen Harris, had chosen to send her to Leasowes High School in Halesowen, West Midlands, six miles from their home, to ensure she got the best possible education. Neil Shaw, the school's headteacher, described Miss Edkins as a "bright and popular student" who was much loved by staff and students alike. Detective Superintendent Richard Baker, of West Midlands Police, said: "This is a tragic case and the victim's family are devastated."