Peter Taylor, whose Panorama film explores the policy that led to the shooting of Jean Charles de Menezes, explains what really happened on 22 July 2005.
By Peter Taylor
Operation Kratos, the highly controversial policy put in place by the Metropolitan Police to deal with suicide bombers, is not for the faint hearted.
Peter Taylor investigates what led to the tragedy at Stockwell station
The word comes from the ancient Greek meaning might, power or strength. The name is not misplaced.
On 22 July last year the operation climaxed with the tragic killing of 27-year-old Jean Charles de Menezes, while sitting in a carriage deep under ground at Stockwell tube station in London.
The young Brazilian was totally innocent, shot seven times in the head by two undercover officers from Scotland Yard's elite firearms unit known as CO19.
It was a disastrous case of mistaken identity. They had been led to believe he was a suicide bomber on the run and had to make a split-second decision. He was not.
STOCKWELL: COUNTDOWN TO KILLING
Wednesday 8 March 2006
21:00 GMT, BBC One
Online at bbc.co.uk/panorama
However terrible those events of that day, they have to be seen in their context.
The 7 July attacks left 52 dead and more than 700 injured. Two weeks later there were four more apparent suicide bomb attacks which failed, and on the morning of 22 July, four suspects were still out there and had to be located and stopped in case they struck again.
The pressure on the police was enormous. With 7/7 all too fresh in the mind, Londoners had to be protected.
But even as late as the last few minutes of his life, Jean's death might have been avoided. As the surveillance officers followed him down the escalator and onto the tube, they may have finally realised that he was not concealing a bomb.
Jean was not carrying a bag and was only wearing a denim jacket that was unlikely to conceal explosives.
But they had no way of transmitting the message. Their radios did not work underground.
Jean's life might have been saved had the radios worked
One call from the surveillance officers, even at the last moment, might possibly have saved Jean's life.
John Stevens told me that, when he was Met Commissioner, he had done all he could to put pressure on the Home Office to provide specialist radios.
"It was a major issue, because if we did not have proper communication with our officers down in the Tube, we were going to have problems.
"In a fast moving situation, you have to inform the officers involved what is taking place.
"Equally importantly they have to get back in touch with you as to what they are doing and why they are doing it. It is absolutely key that communications are working."
Today the situation is still no different. Police officers do have the new state-of-the-art "Airwave" radios but they still don't work deep underground.
The Home Office says that contracts have still to be signed to put the necessary infrastructure in place.
Sight of bomb?
And there may be another possible reason why Jean is dead, despite the fact he was not seen to be carrying or wearing a bomb.
I asked Chief Inspector Martin Rush, who runs the Met's firearms training centre at Gravesend, whether his officers actually have to see a suicide jacket, or what they think may be a suicide jacket, before they open fire.
Jean is buried at Gonzaga, an hour's drive from his parents' home
"No", he replied.
This is not the case in Israel where suicide bombers have been a fact of life for many years.
I put the same question to Major General Mickey Levy, the police commander in Jerusalem between 2000 and 2004, who dealt with 42 suicide bombers.
He said his officers had to be sure they could see a suicide vest or explosives before they opened fire.
So if the CO19 officers did not see any bomb, why did they open fire and how, if at all, were they authorised to do so?
This question lies at the heart of the investigation conducted by the Independent Police Complaints Commission (IPCC) whose findings are now being considered by the Crown Prosecution Service. The CPS will decide whether any police officers should face prosecution.
Although senior officers say that the final decision to use lethal force rests with the person who pulls the trigger, in reality the ultimate responsibility may well lie elsewhere.
Once a Kratos operation is in place, it is commanded by one of a number of specially trained and highly experienced officers at Scotland Yard known as "Designated Senior Officers" (DSOs).
One told me that he reassures the firearms officers under his command that if anyone ends up in the dock, it is him.
In running a Kratos operation, the DSO has a range of code words at his or her disposal to convey instructions to the CO19 officers on the ground. They culminate in one particular codeword that authorises the use of lethal force.
But, in the end, the success or failure of the operation depends on the quality of the intelligence.
So who bears responsibility for the death of Jean Charles de Menezes?
The person in the most exposed position is Commander Cressida Dick, a highly regarded, Oxford-educated Met officer, who was DSO on the day of the shooting.
The programme follows Jean's family in their quest for justice
Above all she needed to know from her surveillance team if the suspect they had been following from a flat in Scotia Road, Tulse Hill, was the 21/7 bombing suspect Hussein Osman. For some time, there was a degree of uncertainty.
However it appears that the surveillance officers finally made a positive identification before the bus that Jean was on reached Stockwell.
I understand that Commander Dick then said something like "Are you absolutely sure", to which the answer seems to have been "Yes".
She then activated the CO19 unit who would have driven at high speed to Stockwell, probably at the very last minute.
The 64,000 dollar question is what instruction did she then transmit to the surveillance and firearms teams at Stockwell? Did she do more than instruct CO19 to stop him going down the tube?
Whether she used the code word authorising the use of lethal force is as yet not known. This is central to the IPCC's investigation.
The problem with Operation Kratos on Friday 22 July was that there was virtually no "fighting time" and, according to Barbara Wilding, it was not one of the scenarios the Met had envisaged and planned for.
Although Kratos policy has been extensively revised since under Assistant Commissioner House, on 22 July it only covered two narrow scenarios: Kratos - a spontaneous event in which a potential suicide bomber is suddenly identified by, say, a member of the public - and there is no prior intelligence; and Clydesdale, where there is detailed intelligence about an attack on a specific target which means that the police have ample time to put their tactics in place.
The problem on 22 July was that strictly speaking the operation fell into neither category. Barbara Wilding said: "What we looked at on 22 July, as I understand it, was somewhere in between."
Stockwell was a double tragedy above all for the de Menezes family but also for the Metropolitan Police whose officers believed they were trying to protect London.
If the suspect had been a suicide bomber, the officers who ran the operation and finally killed him would probably have been decorated instead of facing the possibility of ending up in court.
In the end, as Operation Kratos reached its deadly final act, it turned into a Greek tragedy like its eponymous name.
This special edition of Panorama was broadcast on Wednesday 8 March 2006 at 21:00 GMT on BBC One.