Detectives investigating the murder of a pregnant woman and her unborn baby in Croydon, south London have arrested a third person.
A 25-year-old man is now being questioned by officers at a central London police station after being detained on suspicion of murder.
Kelly Mary Fauvrelle, who was around eight months pregnant, was stabbed to death at a home in Croydon last month.
The 26-year-old's baby, named Riley, was delivered at the scene but later died in hospital.
The baby's father was with his newborn son when he died.
Two people were earlier arrested. One was released with no further action, the second bailed until next month.
Officers previously released CCTV footage of a person they wish to speak to, and are urging members of the public to come forward with information.
Detective Chief Inspector Mick Norman urged: "I am asking members of the public to look very carefully at the footage.
"I know there is not a clear image of the man’s face, but I am certain that somebody will recognise this man from his build, his walk, his run and so on. If you may know who he is, please contact police or Crimestoppers."
In the footage released by the Metropolitan Police, a man is seen walking towards the property in Raymead Avenue, Thornton Heath at 3.11am and running back just over 10 minutes later.
Police are keeping an open mind around the motive and circumstances of the attack, he said, and understand Ms Fauvrelle was alone in her bedroom when she was stabbed.