Jean Charles de Menezes was killed by special bullets designed to cause instant death, the Old Bailey heard yesterday.
They "immediately incapacitate" the victim instead of passing through the body merely causing injuries.
A senior firearms adviser, who was an acting superintendent on the operation, said the decision was made to help police chasing the failed July 21 suicide bombers, who were still at large. The expert, known as 'Andrew' to protect his anonymity, said the bullets would stop a suicide bomber detonating his device.
He told the trial against the Metropolitan Police, which is accused of " fundamental failures" in handling the operation, that he opted for hollow-point 124 grain bullets.
The 27-year-old electrician was blasted seven times in the head after being wrongly identified as a terrorist.
De Menezes: Police used special 'hollow-point' bullets designed to kill instantly | the Daily Mail