There has been a fall in the number of complaints against the police.
Ombudsman Nuala O'Loan made several recommendations to police
The Police Ombudsman annual report reveals there were more than 2,800 complaints against police officers - a fall of almost 100 on the year before.
Almost half of the complaints were received from members of the Protestant community and 37% from Catholics.
The majority of complaints concerned allegations that police officers had failed to do their duty.
Allegations of assault, intimidation or harassment, which used to be the main cause of complaint, represented 37% of complaints last year - a drop of 4% since 2002.
During the year, the PSNI also asked the ombudsman to investigate 72 "serious matters", 58 of which involved the use of CS spray.
Four separate incidents in which people had died were also investigated.
The Police Ombudsman's Office forwarded 149 cases to the Director of Public Prosecution during the year - in 142 it was recommended that no charges be brought against officers.
In seven instances, charges were recommended.
The ombudsman's office also forwarded 57 cases to the chief constable, recommending that officers face disciplinary action.
Ombudsman Nuala O'Loan also made a series of recommendations for improvement in policing policy or practices.
These included a recommendation that CS spray should not be used as a dispersal weapon during street disorder, which has now been addressed by police.