The photographs showed Jean Charles de Menezes's body, his limbs lying at odd angles, his head pulverised by bullets fired at close range, framed by discarded belongings that littered the carriage floor, a puddle of his blood and two long lines of yellow police evidence markers.
It might have proved harrowing for Mr Pereira. But Sir Ian Blair, the chief of the Metropolitan Police, also had reason to shudder when the images were aired on that night's ITV news. For the Oxford-educated policeman, who had claimed his operation was "close to genius", the news of how his officers had shot Mr Menezes threatened to bring to an end a hitherto flawless career.
As the scoop propelled the Brazilian electrician's death into headline news the world over, the credibility of Britain's most senior police officer was on the line. Had he lied about the circumstances of the shooting? Worse, was there a cover-up?
For his critics, Sir Ian had already become something of a hate figure. Branded the "PC PC" for his apparently New Labour leanings, Sir Ian had already endured a destabilising row with his specialist firearms officers, after several were suspended over the shooting of an unarmed man, Harry Stanley, in 1999. In late July, he provoked a row with West Midlands police by publicly criticising their use of a Taser stun gun on one of the suspects for the failed 21 July bombings. The next day, eyebrows were raised when he boasted that the Met's successful investigations into both July bomb attacks were "close to genius".
The leaked Independent Police Complaints Commission documents raise some profound questions about the police tactics on 22 July and its conduct in the immediate aftermath, and demolish the theory that Jean Charles had been acting suspiciously. They also raised suspicions, which Sir Ian has denied with particular vehemence, that there was an attempt at a cover-up.
In the hours immediately after Mr de Menezes's death, the British public were told that his behaviour had given police and army surveillance officers grounds for believing he was dangerous. Dramatic witness statements from Stockwell Tube reported that a man had vaulted the ticket barriers, apparently running from his police pursuers as he was pursued by other men.
One witness, Mark Whitby, told BBC News he had seen Jean Charles - whom he described as an "Asian guy" - being pursued on to the train by armed officers. He had been sitting in the carriage, and saw the incident at close quarters. "As the man got on the train I looked at his face. He looked from left to right, but he basically looked like a cornered rabbit, like a cornered fox.
"He looked absolutely petrified. He sort of tripped but they were hotly pursuing him and couldn't have been more than two or three feet behind him at this time.
"He half-tripped, was half-pushed to the floor. The policeman nearest to me had the black automatic pistol in his left hand, he held it down to the guy and unloaded five shots into him.
"He looked like a Pakistani but he had a baseball cap on, and quite a thickish coat.
But Mr Whitby, who was understandably distraught by what he had seen, was also mistaken. So were the witnesses who believed they saw a man "with wires" poking from his clothing. Yet these accounts immediately gained currency in the media - their credibility quickly given even greater weight by the words later that day of Sir Ian Blair.
By mid-afternoon, the police knew Jean Charles was not a suicide bomber. They also knew that he, a light-skinned Brazilian, did not answer the description of any of the four suspects. But he had one direct connection to the intense police investigation into the failed attacks - he had emerged from a small block of flats at 21 Scotia Road, Tulse Hill, which was home to the terror suspect Osman Hussain, at 9.33 that morning. And he had gone to Stockwell Tube - a station used by the previous day's bombers.
So Sir Ian, as did many of the Met commanders, believed his men were right to treat him as a suspect. But his words that afternoon are coming back to haunt him. He said: "The suspect's clothing and behaviour added to our suspicions." The question being asked is: why?
Sir Ian or one of his deputies was on the phone to the Home Secretary, Charles Clarke, every day during the hunt for the bombers, and would have told him immediately that a suspect had been shot. The next day, the Home Secretary went on holiday, confident that the police had acted correctly, although he must have been warned even as he set off that an innocent man had been killed. He still insists that the police have acted correctly.
However, the Home Office was almost immediately involved in telling Sir Ian that he had to allow the IPCC to investigate, overruling his original request that inquiries into the shooting should be delayed while the hunt forthe attempted bombers of 21 July continued. Sir Ian was told in writing by Sir John Gieve, the most senior civil servant in the Home Office, that the IPCC would have to be called in.
Met officials are adamant that Sir Ian spoke in good faith. But his remarks seemed to be lending credence to the confused impressions of eye-witnesses. The pathologist's report on Mr de Menezes's death from the post mortem on 27 July - five days after he was shot - records that he was told that the Brazilian was followed by police, "vaulted over the ticket barriers, [and] ran down the stairs on the Tube station".
This was untrue. What is more, within 24 hours of the shooting, the police knew that they had killed an innocent man, yet had not apparently taken action to correct misleading stories about him.
Harriet Wistrich, the de Menezes's family lawyer from Birnberg Peirce, believes this information came from police officers present at the post mortem. "It is absolutely critical when a pathologist is given an account of a killing that it is as accurate as possible. It might well affect the way he assesses the body and prepares the evidence," she said.
Within days, the Home Office had added to the "chase" theory by disclosing that the immigration stamps in Mr de Menezes's passport were not officially authorised. Someone, it appeared, had illegally put a disused residency stamp in his passport.
This gave the impression that the Brazilian might have run from the police because he was an illegal immigrant. This was also untrue. The Home Office has since made it clear they are not claiming that the young man knew he was in the country illegally. He may have been defrauded by a "facilitator" who sold him a fake passport stamp.
The evidence collected by the IPCC, which includes CCTV images, shows that he walked calmly through the station, picked up a free newspaper, swiped his Oyster travel pass at the barrier, and walked towards the platform. He ran when he heard the train approaching. He was bareheaded and wearing a light blue denim jacket - not what a bomber would wear to hide a bomb.
The IPCC dossier suggests a police operation mishandled from the beginning. As Mr de Menezes left a friend's flat at 9.33, the police surveillance officer, codenamed Tango Ten, was "relieving himself", and unable to turn on his digital camcorder quickly enough. He stated: "As he walked out of my field of vision, I checked the photographs [of the four suspects] and transmitted that it would be worth
What police said - and what really happened
The police claim: A man of "Asian appearance", behaving suspiciously, is shot dead by police on a Tube train in Stockwell.
The truth: The dead man, Jean Charles de Menezes, 27, was Brazilian.
The police claim: His shooting was "directly linked" to the investigation into the London bombings.
The truth: Mr de Menezes was an electrician and had nothing to do with the London bombings.
The police claim: Witnesses described him running into the Tube station, vaulting the barriers.
The truth: He walked into the station and picked up a free newspaper before entering with a travel pass. He made his way to the platform. He started to run only when the train arrived.
The police claim: Witnesses said he was wearing an "unseasonable" heavy coat, and Scotland Yard said his clothing had "added to suspicions".
The truth: Photographs of the body show Mr de Menezes wearing a blue denim jacket.
The police claim: "As I understand the situation the man was challenged and refused to obey police instructions" - Sir Ian Blair.
The truth: There was no police challenge.
The police claim: Mr de Menezes ran on to the Tube train, tripped and was shot five times by police as he lay on the floor.
The truth: CCTV footage is said to show Mr de Menezes pausing, looking left and right, and sitting on a seat facing the platform. A police witness says Mr de Menezes stood up when the police arrived. The policeman then pinned his arms to his sides and pushed him back in the seat. Mr de Menezes was then shot 10 times - three of the bullets missed.Reuse content