Nicole Smallman, 27, and her sister Bibaa Henry, 46, were found dead in Fryent Country Park, where they had celebrated Bibaa’s birthday on June 7, 2020.
Police were slow responding to their disappearance, and a friend of Nicole eventually found the bodies.
It later emerged that two Metropolitan Police officers took photos of the sisters at the crime scene, posed with the bodies and circulated the images in a WhatsApp group. Both men were jailed and released early.
Their mother Mina Smallman has since worked with several forces, including the Met and Police Scotland, and is in ongoing contact with Met Commissioner Sir Mark Rowley.
She is due speak at the Education Festival at Wellington College on July 3.
She said about her daughters’ deaths: “It was pure anger. We had to search for our girls. The police did nothing. And then we found out about the selfies. I knew it was not an isolated incident. I knew it was part of something much deeper.”
She added: “There are brilliant officers out there. But the good ones are being overshadowed by the bad.
“We don’t want them. Not in the police. Not in schools. Not in the NHS. These are caring professions. They need people who care.”