A youth offending team in charge of monitoring a teenager later convicted of murdering a jeweller has admitted "certain mistakes" were made.
Peter Williams attacked Victor Bates with a crowbar
Probation inspectors said Peter Williams, 19, repeatedly breached his curfew order yet little was done.
Marian Bates, 64, was gunned down in her family shop in Arnold, Nottingham, in September 2003.
The city's youth offending team said a decision could have been made earlier that he had breached the order.
It added most of the recommendations made in a report by Her Majesty's Inspectorate of Probation (HMIP) were also identified in an internal review of the case carried out immediately after Williams' arrest.
"A decision could and should have been made earlier that Williams had breached the terms of his supervision," the team said in a statement.
It added the team had already made "significant progress" in carrying out the actions required.
Mrs Bates' husband Victor said the report showed tagging young offenders was a "complete waste of time".
Williams was released from a young offenders' institution on licence just 20 days before Mrs Bates' murder.
He attacked Mr Bates with a crowbar while his accomplice, who has never been caught, shot Mrs Bates in the chest as she shielded her daughter.
HMIP said in the report that Williams had failed to attend a string of meetings with youth offending and drug workers, education staff and the police.
These were breaches of the terms of his licence which could have resulted in his return to custody.
Williams had also breached a curfew order - which was supposed to be enforced by his electronic tag - on at least six occasions.
Mrs Bates's killer was not properly monitored by the authorities
Private monitoring company Premier failed to inform his youth offending team of this until the morning of Mrs Bates' murder, by which time he had removed the tag completely.
The inspectors also discovered that his case manager was "inexperienced" and had no formal qualifications in youth work, social work or probation.
The report said Williams' case was not managed closely enough.
However, the inspectors pointed out that even if they had acted differently it may not have been enough to ensure Williams was back in custody before the killing.
Mr Bates, 66 branded the report a "complete whitewash".
He added: "He (Williams) was a serial breaker of every condition that they put on him, yet they kept letting him out. It shows that tagging does no good whatsoever."
A Premier spokesman insisted it had been an "isolated case" but said they accepted the report was accurate.
The report did find that the Home Office's statement of operational requirements for electronic monitoring "did not clearly or adequately define" what was required for monitoring curfews.
But Norman Brennan, director of the Victims of Crime Trust, called for tagging to be stopped immediately and an urgent review of non-custodial sentences.
He said: "If the murder of Marian Bates doesn't show the government that it needs to scrap tagging forthwith, I don't know what will."
Williams was sentenced to life in prison for murder in May 2005.