A Belfast doctor who killed his mother had been raised by her "in almost third-world conditions" and in an atmosphere of "intimidation and bullying", a court has heard.
Anne O'Neill, 51, was found in the garden of her parents' home at Ardmore Avenue in Finaghy on 21 October, 2017.
Her son, Declan Kevin O'Neill, 29, attacked her with a chisel.
It was a "brutal killing" during which neighbours heard her screams for help, prosecutors said.
However, relatives asked the court to show "mercy" as Mrs O'Neill, a retired nurse, had been a "controlling personality" who had driven her son "beyond his limits".
The judge will rule on the conditions of O'Neill's sentence next Thursday.
The court was told how Anne O'Neill's children had grown up with "relentless emotional violence" and "domestic abuse".
They slept on mattresses, in a home which had no bathroom and little furniture - their clothes were kept in cardboard boxes.
During the attack, the victim was heard to scream "leave me alone, Declan" and "somebody help me".
She suffered severe head injuries. Her son was arrested at the apartment he shared with his partner a short time later.
Police found the shower had been recently used, clothes were in the washing machine and a bag with a rubber mask, tape and metal chisel was lying in a communal area of the building.
Traces of Mrs O'Neill's blood and hair was found on the chisel and in O'Neill's car.
From the court
by Declan Harvey, BBC News NI
The litany of abuse Anne O'Neill's children claimed they suffered was both shocking and upsetting in court.
As family members watched from the public gallery, Declan O'Neill shook continuously and sobbed in the dock.
At one point, Mr Justice Colton reflected that it was difficult to avoid concluding Anne O'Neill herself had a mental illness.
Defence lawyers said O'Neill, of Malone Avenue, changed his plea to guilty and "surrendered his [legal] fight" in September to spare any further distress to his family.
It was argued he would have been able to argue diminished responsibility due to his mental state at the time of the killing.
"His mother controlled his daily life," the court was told.
The victim's mother said in a statement: "There are too many examples of the controlled life they had to lead for me to begin to explain."
'Our adult lives were destroyed'
The victim's daughter revealed in her statement to the court that her mother had on one occasion "held me by the throat against a wall" and "hit me with a brush".
She said the children had a lifetime of their mother calling them names and "being horrible" and it had "a profound effect".
It was "a very difficult upbringing", she said.
"I always knew the way she treated us was not normal.
"Our whole childhood and right into our adult lives was destroyed," she added.
She said both children were "trapped" and Anne O'Neill "constantly blackmailed" them.
Following his arrest, O'Neill told police in an interview: "I didn't mean to.
"I just couldn't take anymore.
"You don't know what it's like every day - thousands of pounds of debts in my name.
"[She] keeps taking money off me."