Detectives have issued an urgent appeal to trace a man in connection with the disappearance of a teenager who is believed to have been murdered.
Hertfordshire Police said 22-year-old Jack Wall, from Stevenage, was being sought by officers investigating the disappearance of a woman aged in her late teens.
Wall, of Hadrian's Walk, is thought to be blind in one eye and is described as having a distinctive squint.
The missing teenager has been named as Amelia Arnold, a 19-year-old hairdresser from Stevenage. She was last seen on Wednesday, November 7. Despite police efforts, she has not been found.
As part of the inquiry, detectives and scene-of-crime specialists are examining a property in Hadrian's Walk.
Witnesses who may have seen suspicious activity at the address between Wednesday and Friday are also being asked to come forward.
Police want to hear from anyone who may have witnessed anyone acting suspiciously in a white Citroen Berlingo, registration R389 VDP, in the Stevenage area since Wednesday.
Meanwhile, a 41-year-old man from the local area has been arrested in connection with the investigation and is in police custody.
Anyone with information which could assist the inquiry is asked to contact police immediately by calling the non-emergency number, 101.
Alternatively, information can be passed on anonymously to the Crimestoppers hotline on 0800 555111.