Three police officers have been disciplined following a Police Ombudsman investigation into circumstances surrounding the death of Marion Millican.
Ms Millican was shot and fatally wounded by her former boyfriend, Fred McClenaghan, in a laundrette in Portstewart on 11 March 2011.
The PSNI referred to the Police Ombudsman's Office for independent investigation concerns about how police had responded to information they had received prior to the shooting. The Office also received a complaint from a member of the public who had similar concerns.
Police Ombudsman investigators established police had been aware of previous threats made by McClenaghan to kill Ms Millican. In December 2010 they received a report that he had threatened to kill both Marion and himself and had notified her of this threat.
Police became aware of a similar threat on January 25. The person who provided the information on this occasion said they believed McClenaghan had a gun, but could not confirm ever having seen it.
The Police Ombudsman, Dr Michael Maguire, took the view that the police response to the information they received in December 2010 was inadequate; they failed to deal effectively with the later report that he had a gun and they gave no consideration to sharing the information they had with health professionals:
"Fred McClenaghan alone bears responsibility for Marion's death. However, a succession of police failings meant that opportunities to deal with him, either as a suspect or a person in need of urgent mental health care, were significantly reduced or in some cases completely missed," he said.
"The PSNI has informed the Police Ombudsman's Office that it has reviewed its procedures on how to deal with threats to life, taking into account both UK police policy and the recommendations from previous investigations by the Office."