A teenager has been 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 some 90 minutes later.
Officers involved in a major manhunt arrested a 19-year-old suspect in the Hackney area, Scotland Yard said.
The suspect remains 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 on Monday in a grey Fiat Stilo which was abandoned about a mile from her home.
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 were treated for stab wounds.
The man remains 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".