LONDON | A police marksman who fatally shot an unarmed Brazilian man broke down on the witness stand on Friday after describing how he thought his target was a suicide bomber about to blow himself up.
The officer told jurors at an inquest into the July 22, 2005, killing of Jean Charles de Menezes that he thought the man he was pursuing had been identified as one of the failed bombers who had tried to attack London’s transport system the previous day.
“It was left in no doubt as to the type of suspect we were trying to intercept, and they were prepared to take their own lives as well as others and the danger was immeasurable,” said the marksman, who was granted anonymity by the inquest and identified only by his code name, C12.
Mr. de Menezes, a 27-year-old electrician, was followed from his apartment building — which was also home to one of the would-be bombers — and onto a subway train by armed officers who fired seven shots into his head.
The officer recalled how he and another armed officer followed Mr. de Menezes into Stockwell subway station in southern London and onto a train. He said he shouted “armed police” and pointed his gun, but the Brazilian stood up and moved toward him.
“It was at that stage that I just formed the opinion that he’s going to detonate, he’s going to kill us and I have to act now in order to stop this from happening,” the marksman said.
He said he fired three shots as a surveillance officer held Mr. de Menezes down. A second police marksman fired several other shots.
“If there was any alternative, you must believe me, I would have taken it, but I did not have any alternative,” said the officer, who choked back tears as he recalled the events. “I did not believe I had an alternative and if I did not act, members of the public would be killed.”
The inquest was briefly adjourned after the officer broke down on the stand.
The officer said at the inquest that he had been part of a specialist firearms unit since 1998 but had never fired his gun at a suspect until the day Mr. de Menezes was killed.
Friday’s testimony was the first time either of the officers who shot Mr. de Menezes has spoken publicly about the events. The dead man’s mother, Maria Otone de Menezes, 63, and brother Giovani da Silva, 36, were at the inquest to hear him.
The marksman said he offered “sincere condolences” to Mr. de Menezes’ family.
He said he was shocked when he found out that the man he had killed was not a bomber.
“Everything I have ever trained for - for threat assessment, seeing threats, perceiving threats and acting on threats - proved wrong,” he said. “And I am responsible for the death of an innocent man. That is something I have got to live with for the rest of my life.”
The inquest has heard testimony about confused communications between police officers as the London force mounted a huge manhunt for the failed bombers. Tensions were high in the city after suicide bombings two weeks earlier that killed 52 subway and bus passengers.
No one has been charged in Mr. de Menezes’ death, although a court convicted the police force last year of health and safety violations for endangering the public’s safety during the shooting.