The Manchester terror attack - which claimed the life of Sheffield woman Kelly Brewster - might have been prevented if different decisions had been made by MI5, a report has found.
An official report by David Anderson QC found that suicide bomber Salman Abedi was on security services' radar prior to the attack at the Manchester Arena in which 22 people died.
He had twice been a "subject of interest" in MI5 investigations in the years before May's attack, but those investigations were later closed and interest in Abedi was downgraded.
However, fresh intelligence was received about the 22-year-old's activities in the months before the bombing.
The report said security services' review of intelligence on around 20, 000 extremists highlighted Abedi as one of a handful of individuals who warranted "further consideration."
An MI5 meeting to discuss whether Abedi should be further investigated came too late. It was scheduled for May 31, nine days after the attack.
Mr Anderson QC said different decisions might have been taken, but it was unknowable whether Abedi would then have been stopped.
The report concludes that "in retrospect, the intelligence can be seen to have been highly relevant to the planned attack."
The document was produced after the Home Secretary Amber Rudd asked Mr Anderson QC, the former Independent Reviewer of Terrorism Legislation, to assess and report on the police and security services' internal reviews into the Manchester and London terror attacks earlier this year.
While security services came in for criticism, Mr Anderson also said 22 terrorist plots had been thwarted by the authorities in the past four years.
Arbourthorne woman Kelly Brewster, aged 32, was among the victims fatally wounded in Manchester.
She had attended with her sister Claire and niece Hollie who both spent weeks in hospital receiving treatment for their injuries.
Kelly's partner Ian Winslow described her as a "beautiful person."