Charlie Pottins (London, Justice4jean): A killing like that of Jean Charles de Menezes, shot in the head by police on a London Underground train, could happen again, a senior police officer involved in leading the operation has told the inquest into Jean Charles' death.

So far the jury has been given a crash course on police procedures, learning about "Gold" and "Silver" levels of command, designated senior officers(DSO), and the respective roles of SO12(Special Branch), SO13 (Anti-Terrorist branch) and CO19/SO 19 (Firearms) officers.

The inquest has heard from Deputy Assistant Commissioner John McDowall who was "Gold" in charge of the police operation which led to Jean Charles de Menezes' death on July 22, 2005, that he held a briefing for senior officers on the 16th floor at New Scotland Yard that morning, where he set out a strategy for surveillance of premises at 21 Scotia Road, Tulse Hill, after evidence had linked a suspect bomber called Hussein Osman to that address. McDowall said that although he told officers what he wanted, he did not give any direct orders, leaving that to the "Silvers".

DAC McDowell said he had not been aware that no.21 was not a house, but one flat in a block of nine with a common entrance. We have heard how a surveillance team which found this watched people leaving the block that morning before an officer codenamed "Frank" signalled that one person - Jean Charles - "might be worth somebody having a second look".

As we know, the police did not intercept Jean Charles, but followed him as he took a bus to Stockwell. We have now learned he passed two of the plain-clothes surveillance team to enter the station, and went down to catch a train, unaware that he was being followed, and a firearms team was brought in to chase after and kill him.

We watched CCTV footage plainly showing that Jean Charles was not wearing bulky clothing that might conceal an explosive device, as was initially claimed, nor did he leap the ticket barrier and rush down the escalator. That was the firearms officers. They had been issued with special hollowed ammunition designed to cause maximum damage, and they aimed at the head because this is the way they are trained to stop a suicide bomber, But the question remains - if the police feared the man they were pursuing was a suicide bomber, and their main concern was to protect the public, how come they made no attempt to prevent him reaching the tube train?

On Wednesday we heard from Detective Chief Superintendent Jon Boucher, who had been Anti-Terrorist squad officer in the control room at Scotland Yard, advising Commander Cressida Dick. They were watching two addresses linked to the bombing suspects, though it was unlikely the bombers would return to these places, and in fact, the man they were after was not there.

The strategy they had discussed required that "...upon being identified and located subjects will be arrested at the earliest point." DCS Boucher claimed that 'Pat' who was receiving messages from the surveillance team had reported a positive identification of the subject - ie. Jean Charles, though Michael Mansfield pointed out that this was not what the surveillance officer 'Frank' had actually said, and what's more 'Pat' would deny it. Boucher and the control team seem to have changed their minds twice about this, though in the records Jean Charles was referred to throughout as "unidentified male" .

Boucher said he had thought the subject would be stopped at the entrance to Stockwell station. He said he had no detailed knowledge of where teams where during the operation, and there was no map on the wall of the control room. But he denied suggestions it was noisy and chaotic. He also denied knowledge that a wallet with Jean Charles ID had been found on the seat where he was shot. We may remember how at this time it was being reported, and claimed by Sir Ian Blair, that police had killed a terrorist.

Perhaps the most interesting - and chilling - bit came at the end of Boucher's evidence, when Michael Mansfield invited him as a senior officer to say what he thought had gone wrong with the operation.

"I am not sure anything did actually go wrong", DCS Boucher replied. What had they learned or changed? They now had better recording of discussions and decisions taken. Had he misunderstood the question? Coroner Sir Michael White and Michael Mansfield both put it to him again. But Boucher's answer did not alter. "I don't think anything went wrong, sir..."

Michael Mansfield: "On that basis, there is a real risk that it could happen again."

Boucher: "There is sir, yes."

As I write, the news come that Commissioner Sir Ian Blair has been sacked. Whether this is an admission of anything or a removal of piece from the board, the inquest continues.