London's Metropolitan Police (Met) was Thursday found guilty and fined for "exposing the public to danger" during the accidental shooting of Brazilian Jean Charles de Menezes, killed by seven shots to the head because he was mistaken for a terrorist.
"The police forces are not above the law," presiding judge Luis Henriques said following the jury's "guilty" verdict at the Old Bailey Criminal Court in London.
The Met was fined 175,000 pounds (360,000 dollars) for a "grave breach" of Health and Safety regulations, and will also have to cover costs of 385,000 pounds.
The 27-year-old electrician was shot seven times in the head by undercover marksmen on an Underground train in Stockwell, London, on the morning of July 22, 2005, a day after police had foiled a second suicide bombing on London's transport network, following the major attack two weeks earlier.
The verdict Thursday brought immediate calls for the resignation of Met Chief Ian Blair from leaders of the opposition Conservative and Liberal parties, who said Blair's position had become "untenable."
But the police chief, who was in court to hear the verdict, ignored the calls for him to go.
He expressed his "deep regret" for the "tragedy" of de Menezes' death, but said the police had been in a "very difficult situation" on the day of the shooting.
The police force had been in a "race against time" to find the four men who had, a day earlier, attempted to blow up London Underground trains and a bus, two weeks after the major suicide bombings which killed 52 passengers and injured more than 700.
The trial was told that the police believed de Menezes to be Hussain Osman, one of the four men involved in the attempted terrorist attacks the previous day.
In order to prove their point that both men looked similar, the police presented a drawing in court, showing the two men's faces merged together.
"No police officer set out on that day to shoot an innocent man," said Blair, who has insisted that he was not told of the accidental killing until the next morning.
However, commentators said the guilty verdict was a serious blow to London's police force, which was accused during the trial of a "series of catastrophic errors" and "fundamental failures" in the lead-up to the shooting and during the operation.
The ruling made clear that "no personal culpability" was being attached to Cressida Dicks, the commander in charge of the undercover police operation at London' Stockwell Tube station.
During the trial, Clare Montgomery, acting for de Menezes, said her client had "acted no differently from any other commuter" when he boarded the underground train.
"He did nothing to deserve his death ... he was entitled to the protection of the law that day," she said.
But Ronald Thwaites, representing the Met, told the court that de Menezes had "acted in an aggressive and threatening manner that would have been expected from a suicide bomber" when he was challenged by the police pursuing him onto the train.
The trial heard testimony from witnesses describing how an armed officer "pinned" de Menezes to his seat before firing several shots at his head.
In the confusion, one of the officers following de Menezes had almost been shot himself by a colleague, the court heard.
"The fact that the police ended up pointing a gun at another policeman gives you a clue as to just how far wrong the operation had gone," Montgomery said in court.
The prosecution under the Health and Safety Act was brought by the relatives of de Menezes, who have been leading a campaign to achieve justice for his murder, and repeatedly called on Blair to resign.
Family friend Erionaldo da Silva said de Menezes' mother was pleased the police had been found guilty and the family were now looking forward to a "full and thorough" inquest.
"We will not rest in our fight for justice," he said.