Jack Wall arrested by Amelia Arnold 'murder' hunt police
Detectives investigating the suspected murder of a Hertfordshire teenager have arrested a 22-year-old man.
Jack Wall, of Stevenage, was arrested on Sunday morning on suspicion of murdering Amelia Arnold, 19. He is in police custody.
Miss Arnold, also from Stevenage, was last seen on Wednesday and police are continuing to search for her.
A 41-year-old man arrested on Saturday in connection with the investigation remains in police custody.
Police had earlier issued a photograph of Mr Wall and urged him to get in touch with them.
Their investigation is centred on the house he and Miss Arnold shared in Hadrian's Walk in the town.
Det Ch Insp Tim Redfearn, who is leading the investigation, said: "Amelia's family are extremely distraught and are desperate for information on her whereabouts.
"I'd also renew my appeal for anyone who saw or heard any suspicious activity in Hadrian's Walk between Wednesday and Friday to come forward."
He said significant evidence had been found in an area close to Hollybush Lane, Welwyn Garden City.
The area has been cordoned off while further investigations take place.
Det Ch Insp Redfearm said: "We believe evidence in relation to the murder has been left here and we are extremely keen to hear from anyone who lives in the area of Hollybush Lane and saw a white van or anyone depositing of items in the area on Thursday afternoon or evening to make contact with police."
He said Miss Arnold's family were being supported by specialist officers and had requested that their privacy be respected.