The mother of a man shot dead by Greater Manchester Police has vowed to fight to release the secret evidence shrouding part of his case.
Anthony Grainger, 36, was killed during a covert operation in March 2012.
Marina Schofield, from Salford, who lost a legal bid to reveal the sensitive material, said she would continue to try to have it made public.
She said lessons needed to be learned so "no other mother gets that knock at the door".
Mr Grainger was one of a group under surveillance in Operation Shire suspected of planning commercial robberies.
Armed officers had been wrongly briefed that he was armed and violent.
Some of the intelligence has never been disclosed to his family.
Last month High Court judges rejected Ms Schofield's claim that intercept evidence should be admissible in prosecutions where charges relate to "a lethal criminal offence by a state agent".
As it stands, intercept evidence cannot be used in criminal trials but the judges ruled it was up to parliament to decide if the law needed to change.
The Home Office had argued that releasing sensitive material could risk revealing "intelligence methods and capabilities".
Ms Schofield had challenged the secret evidence behind Operation Shire after a prosecution was halted against GMP's chief constable in 2015 over charges that the armed deployment broke health and safety law.
"They've picked the wrong mother this time. I will not stop until I find out the truth about why Anthony's died," she said.
Marina Schofield said she was looking forward to hearing from her son Anthony that night in March 2012.
The eldest of three, he was "her rock" after their father left when they were young boys.
She said: "It was my birthday, my 54th birthday. We stayed in and had a Chinese, me and my husband, and we was in bed by half past 10.
"I thought it strange I never heard from him. I thought why has he not rung? And then you get that knock at half 11 at night, hammering on the door - six police officers."
They had brought the news that Anthony, a father of two, had been killed by GMP armed response. He was unarmed, sitting in a stolen car parked in Culcheth, Warrington.
Ms Schofield said: "I just lost it, I absolutely fell to pieces. Because he knew what it was like not to have a dad, he didn't want them kids to grow up without a dad. But that hasn't happened, has it?"
Despite a public inquiry finding that GMP's errors and failings were to blame for his death, Ms Schofield said she had lost faith that anyone would be held accountable.
The secret evidence has also led to the collapse of a gross misconduct hearing against a firearms commander over evidence he gave to the inquiry, and an Independent Office of Police Conduct investigation into three other senior officers regarding their command and control of the operation.
All have now retired.
"They've wasted millions on different investigations, a public inquiry and what have we got to show for it? It's soul- destroying," said Ms Schofield.
Solicitor Jonathan Bridge, who has acted for Ms Schofield during her nine-year struggle, said: "To date no-one has ever been held to account at any level for the failings that led to the death of Anthony, a situation that means the family must still continue their fight for justice."
Ms Schofield has called on GMP's new chief constable Stephen Watson, who takes over later this month, to ensure lessons had been learned.
GMP said the Home Office had recognised good progress made to address the inquiry findings and recommendations and it remained committed to learning from Mr Grainger's death.
Hear more on this story in One Night in March from Radio 4 on BBC Sounds.