British couple - Thomas Hughes and his partner Emma Tustin - were sentenced for 21 and a minimum of 29 years respectively over the torture and killing of his six-year-old son, Arthur Labinjo-Hughes.
Tustin murdered the boy with a fatal head injury at her home in Solihull in 2020 and took photos of Arthur lying on the floor and sent the images to his father.
Hughes was convicted of the boy's manslaughter.
The trial heard that the boy was subjected to extreme abuse including being poisoned with salt, regular beatings, being starved, and made to stand for hours alone.
Neither of the defendants had shown any remorse, the judge said, as quoted by the BBC. Their behaviour had been "spiteful and sadistic," he reportedly said.
According to the case file, on 16 June 2020, the child suffered a severe head injury after Tustin beat him. She called the emergency service, saying that the boy had fallen and hit his head. Arthur was hospitalised and died the next day.
Arthur's biological mother, Olivia Labinjo-Halcrow, and Thomas Hughes were separated but shared custody of their son until her arrest for stabbing her own partner to death in 2019. According to a victim impact statement read to the court on Friday, Arthur's mother said his death had destroyed her life.