A 40-year-old man has been arrested over the murder of 22-year-old Krystal Hart who was found dead in the hallway of her flat in south-west London.
Paramedics pronounced Krystal Hart dead at the scene
The man was arrested after walking into a police station in south London.
Ms Hart, who was pregnant, was pronounced dead by paramedics called to her home in Battersea, on Friday.
A post-mortem examination revealed she died from two gunshot wounds to the head. Her mother called the killing "senseless and tragic".
Following the arrest of the man on Sunday police said they were not looking for anyone else.
They said they were urgently seeking the whereabouts of a black Golf Driver model five-door car, registration number J326 KCK.
"We believe the suspect was in possession of the car at the time of the murder before later abandoning it - possibly in the south London or Surrey area," police said.
In a statement Deborah Penfold told of her despair at losing her daughter and future grandchild.
"No words can describe the depths of our despair at the sudden and tragic loss of a most precious and beautiful young woman," she said.
"Not only have I lost my daughter but I've lost my grandchild in the senseless and tragic murder of a young woman in the prime of her life."
She said time and privacy was needed to make sense of the "incomprehensible" loss of life.
"Krystal was indescribable in every way," she added.
"She leaves a gap which will never be filled and our lives will never be the same again. The light she shone will never be overshadowed."
Police officers and paramedics were called to Ms Hart's flat shortly after 1100 BST on Friday.
Detectives said they believed Ms Hart's killing could have been related to a "neighbour dispute" dating back "many months".
Ms Hart's stepfather Clive Lawrence, 50, told how he installed cameras in her flat because of the dispute.