Kenneth Newton, 57, and his partner Melanie James, 63, both from Birmingham, have been found guilty of murdering Mr Newton's vulnerable step-brother, Rubin Blount.
Mr Blount, 28, from Tamworth, Staffordshire, died in hospital on 30 November 2022, three days after being admitted. Doctors found he had extensive pneumonia, severe infection, rib and spine fractures, burns, lesions, and grazes. He weighed only six stone (40kg).
Staffordshire Police said their investigation revealed that Mr Newton and Ms James, who were his carers, threatened, verbally abused, and physically assaulted Mr Blount in their home. He had suffered 50 rib fractures, with 47 inflicted in the weeks leading up to his death. Police also found mould and "abhorrent conditions" in Mr Blount's bedroom.
The court heard that the defendants denied Mr Blount access to medical care, leading to a significant deterioration in his health. Det Ch Insp Sean Fitzgerald described the suffering inflicted as "both cruel and deplorable."
Mr Newton and Ms James have been remanded into custody.