Cardiff Crown Court has heard how a son killed his mother with a chainsaw at the home they shared in Ystrad Mynach.
Robert John Owens, 47, killed 75-year-old Iris Owens on Tuesday May 3 this year, while she was hanging washing in the garden at Station House, near Ystrad Mynach railway station.
The court was told how Mrs Owens was strangled, had ribs broken as a result of being kicked, and sustained five separate contacts with a chainsaw.
She died as a result of head and neck trauma.
Owens admitted the murder of his mother at a hearing last month.
Described as “an active and independent lady” by prosecutor Christopher Clee QC, Mrs Owens volunteered for several charities, was a published author, and a bilingual tour guide at Llancaiach Fawr.
The court heard the relationship between Owens and his mother had been “close” and “supportive”, and he had moved into her home after going through a divorce in 2006.
Owens had been chopping wood in the garden of their home with a chainsaw, described by Judge Mrs Justice Nicola Davies as having “excellent safety features”, at around 5pm on May 3, before rowing with his mother, who had returned from a church service.
Mr Clee added: “A neighbour heard the sound of someone calling out and then the sound of a chainsaw.”
Paramedics from the Welsh Ambulance Service arrived at the scene, where they found a “very agitated” Owens, who led them to the garden.
The prosecutor continued: “He told the paramedics: ‘My mother had gone berserk. I killed her and I’m going to jail’.”
Mr Clee also told the court that the precise sequence of events leading up to Mrs Owens’ death were unclear.
Traces of heroin and cocaine were found in the defendant’s bloodstream.
Simon Laws QC, defending Owens, said: “As to the relationship between the pair, that is the background to his remorse. It was a close and loving relationship.
“There is no attempt to minimise what he did. He is devastated by what happened in these few moments of anger when in the garden.”
Adjourning sentencing until tomorrow, Judge Mrs Justice Nicole Davies said: “I was clear in my mind that I do want to very carefully consider the facts of what is a tragic and unusual case.”