Irwin described himself as his mother's carer for at least 35 hours a week, had told numerous agencies that was the case and given up work to perform the role, the court heard.
During the period of time in which she lay on the bathroom floor, Irwin was "going about his daily life" and withdrew money from his mother's bank account.
Irwin made nine separate visits to a nearby shop to buy bottles of cider.
The last time he visited the One Stop store on Fusehill Street was on 27 July - the day before he dialled 999.
Irwin denied gross negligence manslaughter but was convicted, unanimously, by a jury who heard harrowing evidence of his mother's injuries and saw graphic photographs which captured the squalid condition of their home.
Irwin gave no evidence during his trial, jurors heard he had previously told a clinical psychologist he had "tried to help" his mother who, he claimed, had "repeatedly refused" assistance.
Defence barrister Andrew Ford KC suggested Irwin was accustomed to complying with his mother's wishes over many years, and was a man of lower than average intellectual functioning.
"The (999) call was too late by a long way," said Ford. "It must have been a difficult thing to do."
"He has always said to anyone prepared to listen… that he tried to move her and couldn't. She wasn't for being moved. She wanted to stay where she was.
"He is a man who is distressed about all this," Ford added.
Follow BBC Cumbria on X, external, Facebook, external, Nextdoor and Instagram, external and listen to Radio Cumbria on BBC Sounds.

1 hour ago
4






