Police have been given more time to question a 19-year-old man arrested over the murder of a teenager stabbed on her way home from work.
Part-time Laura Ashley shop assistant Asha Muneer, 18, was killed as she walked along an isolated riverside path in Reading, Berkshire, on Monday night.
The suspect, who was arrested the next day, is being interviewed by Thames Valley Police.
Magistrates in Reading granted the force a further 30 hours to question him on Thursday morning and the man remains in custody at Loddon Valley police station in Reading.
Officers can now question him until 4.30pm on Friday, but could apply for another time extension.
The talented A-level student was found next to the River Kennet by a jogger at 8.30pm on Monday. Her handbag was lying nearby.
She is thought to have left work at the Brunel Retail Park more than two hours earlier when the shop closed at 6pm.
Headteacher Tim Royle from Highdown School where the teenager is thought to have taken classes in English, sociology and economics, said everyone at the school was "very, very sad".
He said: "The whole school community is deeply shocked by Asha Muneer's tragic and untimely death and all our thoughts and deepest sympathy are for her family and friends at this terrible time.
"Asha was a much-liked and very talented student who will be greatly missed by all her friends at Highdown and by the staff who knew her and taught her."
