A teenage girl murdered as she travelled to school had tweeted about a sinister man on her bus.
Christina Edkins (16) was stabbed to death just minutes after getting onto a double-decker bus to head for school.
Christina, who dreamed of becoming a nurse, had repeatedly expressed her dislike of travelling by 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 place."
A fortnight later she added: "Eughh hate catching buses, can't wait to start driving."
The schoolgirl, who had been sitting exams at school this week, left her mid-terrace home at around 7am yesterday morning and walked about half a mile to the bus stop to catch the number nine bus to school.
She sat down on the top deck and was settling in for the journey when she was attacked at about 7.30am by a knifeman who was already on board, as the bus was about to stop on one of the main roads out of Birmingham city centre.
A fellow passenger tried desperately to revive her but the teenager died of her wounds.
Police suspect that the murder was a random attack and that Christina did not know her killer. Nobody else was injured.
Detectives launched a huge manhunt involving more than 100 officers assisted by sniffer dogs and firearms specialists.
There was a dramatic development just after 12pm when police spotted a man acting suspiciously behind a supermarket near the scene of the stabbing. Officers gave chase and arrested him on suspicion of murder.
The suspect was named locally as Phillip Simelane (22).
Police said they were aware of Christina's comments on Twitter but stressed that there was nothing to suggest she was being targeted before the killing.