A teenager remained in police custody today after being arrested over the kidnap and murder of young mother Kirsty Treloar.
The 20-year-old victim was abducted from her east London home shortly after 7am on Monday before being found dead in an abandoned car about 90 minutes later.
Officers involved in a major manhunt arrested a 19-year-old suspect at about 1pm yesterday in the Hackney area, Scotland Yard said.
He remained in custody at an east London police station, officers said.
Neighbours said they heard a "hysterical" scream come from the victim's property and a cry of "Please, please, please", before Ms Treloar was taken away.
Her body was discovered with stab wounds at around 8.30am in a grey Fiat Stilo which was abandoned about a mile from her home in east London.
She was pronounced dead at the scene in Ryder Mews. It is understood police believe it to be a domestic incident.
A 22-year-old man and a 24-year-old woman - believed to be Ms Treloar's siblings and named in reports as Dean and Gemma - were also injured in the attack and treated for stab wounds.
The man remained in an east London hospital in a "stable" condition. A month-old baby girl was also taken to hospital as a precaution.
Neighbours expressed disbelief as forensics officers examined both scenes which were cordoned off with police tape. A tarpaulin covered one of the ground-floor windows of Ms Treloar's home in Brownlow Road.
One neighbour, who asked not to be named, said he heard what sounded like a window breaking early this morning and a person shouting "Please, please, please".
A man believed to be Ms Treloar's stepfather is understood to live at the same address. Neighbours said he was employed by Hackney Council.