An allegation that police in Northern Ireland colluded with an IRA killer to prevent his being charged with murder because he was an informant was dismissed by the Police Ombudsman last night.
Nuala O'Loan said an investigation had found no evidence police colluded to protect the gunman who shot and wounded a magistrate and killed his daughter more than 20 years ago.
She said she also found no evidence that police had prior knowledge of the attack in south Belfast or that it could have been prevented.
But for the second time in a week she hit out at Special Branch, saying it had failed again to pass on all the information it had that could have been relevant to officers investigating a murder.
Resident Magistrate Tom Travers and his family were attacked as they left Mass at St Brigid's Catholic Church in Derryvolgie Avenue in April 1984.
Two men ran towards Mr Travers shooting him six times and fatally wounding his daughter Mary.
A woman, Mary Ann McArdle, was arrested shortly afterwards as she walked a dog along the nearby Malone Road. She was found in possession of two handguns - hidden in surgical stockings - and a grey wig.
She was later convicted of the murder of Mary Travers and attempted murder of her father.
A man known as Man A, whom Mr Travers identified from police photographs and an informal ID parade as the man who shot him, was acquitted of the same charges.
Twenty years after the murder, a Sunday newspaper published articles that suggested Man A was a Special Branch informant and a "protected species" .
Mr Travers asked the Ombudsman to investigate the claim - later withdrawing the request - but Ms O'Loan decided it would be in the public interest to complete the investigation.
She said yesterday she had found "no evidence that the RUC protected anyone from prosecution, that their investigation of the murder was deliberately frustrated or that they had any prior knowledge of the attack" .
A thorough analysis of RUC intelligence records found nothing to indicate that the Travers family would be attacked, nor any intelligence that would have allowed the police to prevent the attack, she said.
The Ombudsman added: "While I cannot confirm or deny whether Man A was an informant, I have found no evidence that he was protected from the law."
She was satisfied police had made substantial efforts to bring the perpetrators of the attack to justice.
She said that while she did not find Special Branch had frustrated efforts to get evidence from the search of a property in the Malone area that was suspected of being used as a safe house, she was critical of the branch.
"An analysis of intelligence relating to this case shows that Special Branch failed to share all relevant intelligence with the murder investigation team," she said.
Ms O'Loan added: "It is also totally unacceptable that two guns used in this attack have since either been lost or destroyed."
She revealed a file has been sent to the Public Prosecution Service (PPS) regarding a former RUC officer who is alleged to have told Mr Travers he failed to secure evidence from a location following the murder.