Police discovered David Varlow's body at his home on Manor Lane in Halesowen after his brother and neighbours expressed concern about his disappearance.
The house had been ransacked, and the 78-year-old had been strangled with a telephone cable.
Adris Mohammed's DNA was found on the handle of a knife, the handle of a pair of scissors, and the phone cable found at the scene.
A thorough investigation revealed that Mohammed had targeted Mr Varlow three times in total.
Mohammed, 44, of Icknield Port Road, Birmingham, was found guilty of attempted burglary at Mr Varlow's home on 24 October, aggravated burglary on 3 November, murder, and fraud following a trial at Birmingham Crown Court.
On November 11, he was also convicted of another burglary.
Swan, 42, of Winson Green Road, was found guilty of burglary and fraud on November 11th.
Swan was sentenced to six years in prison.
"Mr Varlow suffered an appalling ordeal, being tied up and essentially left for dead by a man whose only interest was to steal from him," said Det Insp Ranj Sangha, who led the investigation.
We believe Mohammed went back to Mr Varlow's house for the third and final time, knowing he was either still imprisoned or dead.
Instead of doing the right thing and calling for help, he continued to steal from him, with Swan assisting.
"Fortunately, burglaries involving this level of violence are uncommon, but that will be of little consolation to Mr Varlow's family."
"I hope that the verdicts today provide some solace to his family that we were able to obtain justice from him."