Peers are questioning Britain's top law officer Lord Goldsmith about proposed changes to the law on euthanasia.
Ms Lawson attempted to kill herself over a 26 hour period
The attorney general appears before a Lords probe after it emerged a man who comforted his sister during a 26-hour suicide ordeal will not face charges.
Graham Lawson sat with sister Sue as she repeatedly failed to kill herself with a plastic bag "howling" with grief before succeeding the eighth time.
Lord Joffe's private members' bill would legalise assisted suicide.
When Mr Lawson's sister died after suffering from multiple sclerosis for 14 years, he was arrested on suspicion of aiding and abetting suicide.
"I was arrested, stripped of my clothes, photographed and made to feel like some kind of murderer," he said.
"As far as I knew, I was just being compassionate."
In another case less than a week ago, ex-policeman Brian Blackburn escaped a prison sentence after helping his wife, cancer sufferer Margaret, die but then failing with his own suicide.
The widow of a British man taken abroad for an assisted suicide said Lord Goldsmith should back Lord Joffe's bill.
Win Crew was watching the peers' committee session which coincides with the second anniversary of her husband Reg's death in a flat owned by Swiss organisation Dignitas in Zurich.
Mrs Crew said: "Nearly 600 British people have become members of Dignitas because our law does not provide them with a right to a good death.
Mr Lawson heard on Wednesday that he would not face charges
"It forces people like Mrs Blackburn to ask her husband to cut her wrists and end her life as a last act of love.
"It took her more than 20 minutes to bleed to death.
"It forces people like Reg to make difficult journeys abroad in search of a gentle and dignified way out. That is no way to treat a dying man."
Legal advice only
Mrs Crew had to wait seven months before she was told she would not be prosecuted by British police.
The House of Lords committee on the Assisted Dying for the Terminally Ill Bill holds its final evidence session on Thursday.
A spokeswoman for Lord Goldsmith said: "The attorney has been asked to give legal advice on the existing law and not to express his or the government's view on the proposed changes.
"He is appearing in his role as a legal adviser to Parliament."