Police made "investigative failures" in a probe into a 1992 mortar bomb attack which claimed the life of a young female officer, according to Northern Ireland's Police Ombudsman.
Constable Colleen McMurray, 34, was in a police car which was hit by an IRA mortar bomb as it travelled along Merchants Quay beside the canal in Newry on 27 March 1992.
She suffered serious injuries and died in hospital, while another officer who had been driving the car, received life-changing injuries.
In an examination of the police investigation of the attack, Police Ombudsman Marie Anderson found no evidence that officers were in possession of information which, if acted upon, could have prevented the attack.
However the Ombudsman found that police failed to disseminate intelligence about a police informant amid other investigative failings.
Constable McMurray and her colleague had been returned to Corry Square Police Station after providing security support to officers entering the town for a change of shift, while also providing routine community policing.
The Ombudsman said it was standard operational practice at the time for RUC officers to provide this security support for their colleagues.
Ms Anderson identified that RUC Special Branch did not provide colleagues with information about people it suspected were in the IRA and may have been involved in the attack.
She said this had the effect of undermining the RUC investigation, with several people never being treated as suspects.
"Special Branch had significant intelligence about Person A's possible role in the development of detonation technology and possible links to previous IRA activity," she said.
"In my view he ought to have been treated as a suspect but I have not been able to identify any legitimate reason why this did not happen.
The Police Ombudsman also identified deficiencies in suspect and arrest strategies, failures to investigate evidential opportunities and failures to link prior attacks, which also involved the use of "flash initiated" technology.
The Police Ombudsman's investigators interviewed more than 90 witnesses, including 35 retired police officers.
Ms Anderson established that, from the outset, the CID suspect strategy relied heavily on the intelligence held within Special Branch.
However, she found that the dissemination of information from Special Branch to the RUC investigation team was inconsistent.
The investigation also established that the attack occurred when Constable McMurray and her colleague were carrying out routine policing duties and serving their community in circumstances where the threat level in Newry was high.
She added: "The dedication of many police officers, often at great personal risk, to protect the public and their colleagues, represents high standards of professionalism."
The PSNI has been contacted for a response.
