A PSNI investigation into a case of attempted murder in Co Antrim was hindered by "significant failings", the Police Ombudsman has reported.
Nuala O'Loan's office made the criticisms following examination of the police inquiry into an assault on Gerald McRandal, a 33-year-old Catholic, in Larne in October 2002.
Her investigators uncovered "investigative errors" and identified a shortage of police officers in the town at the time of the crime.
Just three officers were on patrol duty covering a population of 30,000 at the time of the assault, which left Mr McRandal brain damaged. Only two officers were able to attend the scene of the attack.
Two people were subsequently charged in relation to the case but their trial collapsed in early 2004. The report cited "insufficient officers on duty to deal with a major incident" and the failure to request assistance from neighbouring areas.
It also said two officers who attended the scene made "a major error in judgment" by deciding to leave the area in search of the attackers rather than stay to preserve the scene and any forensic evidence.
According to the Ombudsman's office the case fell following the withdrawal of eight witnesses and the failure of a police officer to disclose a notebook she had used on the night of the attack.
Mrs O'Loan has recommended that one officer be disciplined and another be sent for additional training. She acknowledged that many aspects of the PSNI investigation were followed "with due rigour".
However she also reported: "The initial police response was inadequate and a number of serious investigative errors occurred."
The report added: "The failure to cordon off and protect the scene following the attack was a major failing and rendered any evidence from the scene virtually worthless.
"This was compounded," the report asserts, "by the fact that police failed to inform defence solicitors about an unofficial notebook containing information central to the case.
"It is clear that while these investigative failures did not on their own cause the collapse of the attempted murder trial, they did further weaken a case in which eight key witnesses had already withdrawn their evidence." It was also revealed that the unofficial notebook was not made known to the solicitors representing the defendants.
According to the Ombudsman's office when the prosecution was made aware of its existence and the reference to the name of an accused, a decision was made to withdraw all charges. Mrs O'Loan has recommended to the PSNI that it ensures investigations are fully staffed; that pre-trial reviews are performed in major cases; that witness protection schemes are reviewed; and that the McRandal family are reassured that the investigation is still active.
The PSNI responded saying it would consider Mrs O'Loan's findings and take on board any recommendations. In a statement it pointed to reforms enacted in the interim, saying: "Since this incident, the police service has restructured and the crime operations department is in place to assist in the effective investigation of serious crime. A lot of work and training has been carried out in terms of crime scene investigation. Any other lessons to be learnt will be studied closely and taken on board."