Miss Beattie died from asphyxiation after McKevitt broke several bones in her neck.
Wales, 44, was jailed for eight years for manslaughter.
Judge Roberts said he accepted the pair thought the house – which belonged to Miss Beattie’s full-time carer Alf Burgess – would be empty.
He also said he believed McKevitt had intended to hurt Miss Beattie but said he could not be sure he had intended to kill her.
Judge Roberts told Wales: “McKevitt put his arm around her neck and squeezed. She could not breathe and died.”
McKevitt, of Phoenix Brow, St Helens, and Wales, of Bright Street, Everton, already admitted burglary.
They received two- year and three-year concurrent terms for that charge respectively.
McKevitt has already served 208 days on remand while Wales has served 223 days.
