A young NSW man who stabbed his mother to death as a teenager is due to be sentenced.
Simone Mottram was murdered by then-19-year-old Bradley Craig Mottram at their Inverell home in October 2015.
He hit Ms Mottram over the head with a bottle of bourbon and stabbed her in the chest, neck, upper abdomen and face after she said something that made him snap.
Mottram is expected to be sentenced in the NSW Supreme Court on Thursday after pleading guilty to the killing.
Ms Mottram's father, Leopold Purer, said he nearly collapsed and was in disbelief when police arrived at his doorstep to tell him his daughter was dead and his grandson had been arrested for murder.
"It has been shocking to discover in myself a depth of anger so corrosive that it makes me capable of having violent thoughts of retribution against my grandson," he said in a victim impact statement.
The court has previously heard Mottram had a dysfunctional upbringing and struggled in the lead-up to the killing with substance abuse and deteriorating mental health.