That included taking a “selfie-style” image which Lewis had superimposed his face on.
The Metropolitan Police officers had been assigned to protect the crime scene but instead took “inappropriate” and “unauthorised” photos before sharing them on social media.
Their “shameful” behaviour also featured them describing the victims as “dead birds” on WhatsApp groups.
The men disregarded the victims’ privacy for “a cheap thrill” or “some form of bragging rights”, which undermined trust and faith in police, the judge at London’s Old Bailey court said.
Social worker Henry and freelance photographer Smallman were killed in June last year as they celebrated the younger sister’s birthday at a late-night picnic.
Danyal Hussein, 19, was sentenced to life in prison earlier this year for murder after telling the court he had made a pact with “a demon” to kill women.
The women were reported missing by friends and relatives but police officers failed to properly record and act on the information.
As a result, the sisters’ family and friends went out to search themselves and the next day found their bodies in the park.
The Met has already apologised to the black victims’ family, who have accused their initially botched investigation of being tarnished by racial bias.
In victim impact statements read in court, family members described the police defendants as a “disgrace”.
The women’s mother, Mina Smallman, said the officers’ actions were a “betrayal of catastrophic proportions” and a “sacrilegious act”.
Earlier this year Met officer Wayne Couzens wasfor raping and murdering a 33-year-old marketing executive, after falsely arresting her on the pretence she had broken coronavirus restrictions.
As well as undermining confidence in the force, that case shocked the country and brought renewed attention on violence against women and girls – and how police respond.
Additional reporting by Associated Press