Research into how armed police react in the highly charged seconds before pulling a trigger has exonerated many in the US. It will be investigated by British police.
Mr Menezes was shot on the London Underground the day after failed bombings
Harry Stanley, Jean Charles De Menezes and Mohammed Abdul Kahar: three innocent men shot by the Metropolitan Police.
In the last 12 months the Crown Prosecution Service announced none of the officers involved in these shootings would stand trial. In fact, no officer has been convicted over any of the 24 fatal police shootings in the past 10 years. For many it smacks of a cover-up.
The day after the CPS announced its decision not to charge the two officers in the Stanley case The Independent splashed on its front page the headline: Shot dead by police: 30. Officers convicted: 0.
When armed police make mistakes, the consequences can be fatal and public confidence seriously damaged.
"As a firearms officers you're either a hero or a murderer," says former Metropolitan Police commissioner Lord Stevens.
Many people are left with the impression that the police are getting away with murder. But new research, instrumental in the CPS decision not to prosecute the officers in the Stanley case, paints a very different picture. It has helped many officers in the US avert conviction when they have killed an innocent civilian.
At the forefront of the research is Dr Bill Lewinski, who argues that the problem with public perception arises because the our "knowledge" comes from fiction.
"Everybody in our nation, including law enforcement, gets their training about police shootings from Hollywood," says Dr Lewinski, professor of sociology at Minnesota State University.
That ignorance extends to police, judges and juries. It wasn't until Dr Lewinski started conducting experiments in the early 1990s that anyone had looked at how quickly suspects could move and how long it took police officers to react to that movement.
Turns to run
He discovered that in the two seconds it takes an officer to draw and pull the trigger, a suspect can fire nine rounds. A person can turn and move as much as 13ft (4m) in one second.
So an officer facing an attacker may decide to shoot - and later swear they were facing them - when in reality their victim has turned to run and been shot in the back.
In the US, an astonishing 70% of victims of police shootings are shot in the back or the side.
Harry Stanley was shot on the way home from the pub
Something like that is said to have happened when Insp Neil Sharman and PC Kevin Fagan shot and killed Harry Stanley in September 1999. Stanley was carrying a table leg and not a sawn-off shotgun, as they had been told.
The officers insisted he turned and faced them pointing the "gun" directly at PC Fagan. But the fatal bullet struck Stanley in the back of the head.
Their story did not match the evidence and they could not remember key details. It looked like they were lying.
Arrested on suspicion of murder in June 2005, the officers hired Dr Lewinksi. His theory of what happened in those fatal split seconds helped persuade the CPS not to charge the officers, although Stanley's wife, Irene, called the decision an "injustice".
By extension, Dr Lewinksi's findings raise serious questions about all police shootings.
As well as his findings about police officers' reaction times, Dr Lewinski has made some extraordinary discoveries about what happens in their brains.
His latest study aims to find the limitations of an officer's recall of a shooting. He has been hired by the Police Federation and will be conducting the experiment later this month in London with Metropolitan Police officers.
In a pilot study in Minneapolis in August, the results were alarming. The officers did not know how many shots they fired and their description of the suspect was inaccurate.
"One of the things lost in the stress response is the counting. Mathematical ability is certainly suppressed. We know that people can't think and shoot simultaneously in this kind of high stress situation," says Dr Lewinski.
If police officers cannot remember key details, it raises serious concerns about the reliability of their evidence. But it does not mean they are lying.
The CPS has said it will take this into consideration in future cases.
"Operational officers will encounter stress threat danger that may not come to most members of public once in a lifetime," says Chris Newell, CPS principal legal advisor.
"It would be stupid on our part not to be alive to the fact that people under stress won't necessarily act in a wholly rational way and won't necessarily recall events with the clarity that hindsight can bring.
The world has changed since Harry Stanley was shot in 1999. In the age of the suicide bomber, the stakes have been raised and pressure on firearms officers has been further magnified.
Police critics and the police themselves accept more tragic accidents are an inevitable consequence of human frailties.
"There will be incidences," says Metropolitan Police Assistant Commissioner Tarique Ghaffur, "and this is what the public has to understand, when people will be shot in the interest of safety to the community, and in the interest of safety to the officers."
Panorama: When Cops Kill was on BBC One on October 15 2006.