The mother of two sisters murdered in a park said her grief had "been taken to another place" after two officers were suspended amid allegations they took selfies next to their bodies.
Nicole Smallman and Bibaa Henry were stabbed to death at a park in Wembley earlier this month.
Mina Smallman has complained about the Met's initial response - saying she had to organise a search for her daughters.
No-one has been charged with the murders.
Speaking to the BBC, Mrs Smallman, the former Archdeacon of Southend, said the pictures "dehumanised" her children.
"They were nothing to them and what's worse, they sent them on to members of the public," she said.
Senior officers from the Met and the Independent Office for Police Conduct (IOPC) personally visited the family to explain what had happened after they were made aware of the alleged photographs.
Mrs Smallman said she was told the photos showed the girls' faces and she fears the images will appear on the internet.
"This has taken our grief to another place," she said.
"If ever we needed an example of how toxic it has become, those police officers felt so safe, so untouchable, that they felt they could take photographs of dead black girls and send them on.
"It speaks volumes of the ethos that runs through the Metropolitan Police."
The IOPC said the pictures were allegedly "shared with a small number of others", adding the Met was "handling matters involving those members of the public who may have received those images".
Yesterday evening, the Met said two officers had been arrested on suspicion of misconduct in public office and suspended from duty.
Met Commissioner Cressida Dick said she was "disgusted" with the allegations against the officers.
Mrs Smallman said she had coordinated a search operation on weekend her daughters died and it was Nicole's boyfriend, Adam, who found the sisters' bodies and the murder weapon.
She says the police were "making assumptions" when they didn't immediately respond when the sisters were first reported missing.
"I knew instantly why they didn't care. They didn't care because they looked at my daughter's address and thought they knew who she was.
"A black woman who lives on a council estate."
Ms Smallman, 27, had been with friends celebrating Ms Henry's 46th birthday at the park on the evening of 5 June.
Detectives believe they were killed by a stranger who repeatedly stabbed them in the early hours of 6 June - their bodies were not found until the following day.
Forensic officers have since been searching a large area of the park including a pond and have trawled through hundreds of thousands of tonnes of rubbish that was accidently cleared from the scene.
Detectives believe the killer received injuries in the attack "which caused significant bleeding".
The IOPC is also separately investigating how the Met handled calls from worried family and friends of the sisters after they went missing.