The Police Ombudsman has concluded that police were justified in discharging 24 impact rounds during serious disorder in the Ardoyne area of Belfast on Monday 13 July 2009.
Trouble flared on the Crumlin Road before Orange Order lodges were due to return via the route from the main Twelfth of July demonstration.
In the days before the parade, police had received notification of a legal protest against the parade by the Ardoyne Parades Dialogue Group. They had also received information suggesting that dissident Republican elements were planning an illegal sit-down protest.
Shortly after 4pm on the day of the parade police learned that hundreds of petrol bombs had been stockpiled in the Ardoyne area.
Within minutes of receiving this information serious disorder broke out. Youths with their faces covered attacked police with paint bombs, bottles, bricks and other missiles.
By 6.30pm petrol bombs were also being thrown at police. At 6.48pm the use of AEPs was authorised by a police commander, who also authorised the use of water cannon five minutes later. Both were used over the course of the next few hours, with authorisation for use being withdrawn during periods when the disorder subsided.
The first AEP was discharged at 7pm, by which stage police had come under attack with bricks, bottles, masonry, fireworks, petrol bombs and blast bombs.
24 baton rounds fired, 11 struck their targets.
Of the 24 rounds discharged before the end of the disorder, police reported that 13 had struck their target, with 11 misses.
They included rounds discharged at a man who attacked police with a six-foot-long metal fence spike, another at a man who was pushing a hijacked van towards police lines, and another at a man who was using a scaffold pole to try to prise open the door of a police Land Rover. The vehicle was one of a number which became surrounded by rioters in the Balholm Drive area.
Other rounds were discharged at people who were identified by police as having been involved in throwing petrol bombs and other missiles at police, including some who had dropped petrol bombs onto officers from the rooftops of nearby shops.
Shortly after 8pm a gunman appeared in the Estoril Park area and a shot was fired at police. He was identified by trained firearms officers using laser sights, and disappeared into the crowd, having initially appeared to be preparing to fire a second shot.
During their investigation of the circumstances of the AEP discharges, Police Ombudsman investigators analysed 25 separate video recordings of the disorder and over 13 hours of police radio transmissions. Police files, including training records and documents relating to the planning for the event, were also examined and found to be in order.
Police conducted extensive consultation with Orange Order and community representatives in a bid to avert disorder.
These revealed that police had conducted extensive consultation with both representatives of the Orange Order and local community groups, prior to and during the disorder, in an attempt to defuse tensions.
In addition, Police Ombudsman investigators contacted the mother of a 13-year-old who media reports suggested had been injured by an AEP during the disorder. The youth's mother declined to make a complaint on behalf of her son.
Having analysed all the evidence, the Police Ombudsman, Mr Al Hutchinson, concluded that the police operation had been well-planned and complied with all legal requirements and national police best practice.
He said the use of AEPs by police was a "justified, necessary and proportionate" response to the level of violence which had been directed at its officers.