Stephen Farrow displayed no emotion in court earlier as the jury returned their verdicts after spending eight-and-a-half hours' deliberation.
He stood silently as the judge told him he would spend the rest of his life in prison.
Former pupil Verity Worthington spoke to Central News recently when she described Betty Yates as a teacher who "brought real life to the class room" with parties under the tables, cherry walks and summertime lessons on the grass outside.
Freddie Starr, who was arrested yesterday by police officers investigating the Jimmy Savile abuse scandal, has returned for further questioning.
The Metropolitan Police confirmed a man in his 60s from Warwickshire is being interviewed again today.
For more on this story see ITV News
Mr Justice Field told Stephen Farrow at Bristol Crown Court today:
"On January 2 this year you somehow got into Betty Yates's home in the afternoon or early evening ...
"You struck Mrs Yates from behind with a heavy walking stick, hitting her hard at least twice to the back of the head with the rounded, bulbous handle.
"You hit her with such force that the walking stick splintered ...
"You then arranged her body and you put a pillow under her head.
"I am quite sure that having done that, you then inflicted the four stab wounds which you inflicted.
"You left the knife in the fatal wound - the wound that was going to bleed the most profusely."
David Yates, the son of murdered retired teacher Betty Yates spoke outside of court after Stephen Farrow received two life sentences for murder.
He said "we should all be relieved and thankful Farrow is off the streets of Britain today. As in his words that had he not been caught he would have continued to kill others and leave more misery in his wake."
Karen Flellow runs a Victorian tea room, Betty was a customer she knew well. She was a member of walking groups and used to visit her shop and sit beside the window with friends.
Mrs Flellow has suffered nightmares since the loss of her friend.
The families of the retired teacher and vicar murdered by Stephen Farrow have said in a statement they "take some comfort from today's conviction but "nothing will compensate the families...for their losses."
"The sentence today reflectsd the brutal nature of these crimes and the devastating effect they had on the families of these victims".
Betty Yates the retired teacher was found two days after her murder lying in her hallway with her head resting on a cushion.
The court heard she was found with a knife still embedded in her head after being stabbed four times and beaten with a walking stick.
A swab taken from the scene represented a "one-in-a-billion match" as a mixture of DNA belonging to the Yates and Farrow, the court heard