It has been announced that the Metropolitan Police will face charges over the fatal shooting of Jean Charles de Menezes under health and safety laws.
How many officers were investigated about the Menezes shooting and what was the final CPS recommendation?
The IPCC's report "addressed the individual actions" of 15 officers to establish whether any had committed criminal offences.
The CPS said there was "insufficient evidence" to bring a prosecution against any of the individual police officers involved in the fatal shooting.
A "realistic prospect of conviction" would be required for a prosecution to be justified.
Who, if anybody, is going to be prosecuted over the fatal shooting?
The office of the Metropolitan Police Commissioner is to be prosecuted under sections 3 and 33 of the Health and Safety at Work Act (1974) over the death of Mr Menezes.
The sections relate to protecting non-employees from the consequences of an employer's actions or those of its staff, and also covers making false entries in official documents.
What does the Health and Safety at Work Act require?
The Health and Safety at Work Act stipulates that the Metropolitan Police should ensure its operations do not put the public at risk.
The relevant part of the Health and Safety At Work Act which applies to the Menezes case states: "It shall be the duty of every employer to conduct his undertaking in a such a way as to ensure, so far as reasonably practicable, that persons not in his employment who may be affected thereby are not thereby exposed to risks to their health and safety."
What could the penalty be?
The penalty on conviction is an unlimited fine. If previous cases involving other organisations are anything to go by, this could run into millions of pounds.
The decision to bring a prosecution under the act may lead to a criminal trial.
The strategy used to deal with suspected suicide bombers and the tactics used on the day of the shooting would be raised in court, and it is likely senior officers would be asked to account for what happend.
What do the family of Jean Charles de Menezes believe should happen?
They believe that individual firearms officers and those involved in the surveillance operation should also be made accountable for their actions - through criminal prosecution.
Has the Met faced a high-profile prosecution under health and safety laws before?
The Health and Safety Executive (HSE) was criticised in 2003 after spending an estimated £3m on a failed prosecution against two predecessors of Met Police Commissioner Sir Ian Blair.
Lord Stevens and Lord Condon were taken to court by the HSE for failing to protect their own officers after one died and another was seriously injured when they fell through roofs while pursuing suspects.
However, they were cleared by a jury at the Old Bailey in June 2003.
Mr Justice Crane condemned the HSE's decision to mount the prosecution, saying the "vast sum" it cost to bring the case might have been "better spent" elsewhere.
Will the decision of the CPS have any impact on Sir Ian Blair's position?
It is not yet clear what effect, if any, the decision will have on the Met Police commissioner's position.
But the CPS stressed he is not being personally prosecuted.
However, the decision not to prosecute individual officers over the incident may lead to the role of Sir Ian being scrutinised, as he heads the Met.
When will we see the full IPCC report?
The report was initially delayed until the autumn to avoid prejudicing related legal and disciplinary actions. But now it could be delayed further so as not to prejudice the trial.