A mother convicted of murdering her disabled son by injecting him with heroin at a Hertfordshire care home has been jailed for life.
Frances Inglis, 57, of Dagenham, Essex, denied murdering Thomas Inglis, 22, on 21 November 2008 and an earlier attempt to kill him on 4 September 2007.
But a jury at the Old Bailey found her guilty of both charges. She must serve a minimum of nine years.
Mr Inglis suffered brain damage when he fell out of an ambulance in July 2007.
The jury reached their verdicts by a majority of 10 to two after deliberating for more than six hours.
Alex Inglis: "All of the family and Tom's girlfriend support my mum 100%"
There were cries of "shame on you" from the public gallery as the verdicts were read out.
Before the jury went out to deliberate, Judge Brian Barker told them "there is no concept in law of mercy killing - it is still killing".
Judge Barker said there was no doubt Ms Inglis had tried to take her son's life in September 2007 and succeeded using an "identical" method 14 months later.
In summing up, the judge said the background of "tragedy and grief" will have struck a chord with all who had heard it.
He said: "It would be extraordinary if we didn't feel empathy with the family and what Mrs Inglis had to face."
During the trial Inglis said: "For Tom to live that living hell - I couldn't leave my child like that.
"I did it with love in my heart, for Tom, so I don't see it as murder."
Inglis told the court she had started to research her son's condition on the internet within days of his accident.
She also claimed she had to beg hospital staff to give him some relief for his "terrible pain".
Detectives investigating the first incident in September 2007 found notes stored under the stairs at her home in Dagenham, east London, the Old Bailey heard.
One said: "People keep saying Tom isn't suffering. How do they know? Can they know the terror of knowing you cannot control anything anymore?
"Can they know the agony of being denied pain relief just to see his reaction?"
She later told police: "When I wrote this I was sort of off my head really," the court heard.
Neighbour Sharon Robinson said Mrs Inglis wanted to know where she could get heroin
Inglis said she was convinced the doctor treating her son at Queens Hospital in Romford, Essex, was lying about his chances of recovery.
The jury heard from Inglis's other son Alex, who said his brother's injuries had driven his mother almost "insane".
Following the first murder attempt in September 2007, Mr Inglis was moved to the Gardens nursing home in Sawbridgeworth, Hertfordshire.
His mother was not supposed to visit him as part of her bail conditions.
But on 11 November that year Inglis visited, pretending to be her sister and signing in with the name Atkins, jurors were told.
When a nurse went to Mr Inglis's room she found his mother, who told her she had HIV and threatened to spit at her before shutting the door, the court heard.
'I injected him'
The nurse went for help to get into the room but when she reached the patient it was clear he was dead, the court heard.
Ms Inglis said: "I held him, told him I loved him, told him everything was going to be fine, took the syringe, and I injected him in his thigh and his arm.
"I knew I had to help him. I asked myself what Tom would want. He wouldn't have wanted to live like this.
"I asked myself what I would want. I would want someone to love me enough to help me die.
"That's why I thought heroin - a painless, peaceful death. He went to sleep. He was at peace. I stayed with him."