The commander of the police operation that led to the shooting of Jean Charles de Menezes told yesterday how she ordered armed officers to stop the Brazilian after wrongly being advised five times that he was a suicide bomber.

Deputy Assistant Commissioner Cressida Dick told a court how the electrician had to be arrested as a potential terrorist because he looked nervous and agitated.

Giving evidence on the first day of the Metropolitan Police’s defence against claims that they had made a “catastrophic” series of errors, she said that it was feared the suspect was Hussain Osman, the 28-year-old terrorist who a day earlier had tried to detonate a bomb on a Tube train.

She said that her surveillance monitor, named only as Pat, had said three times that Mr de Menezes was Nettle Tip, the codename for Osman.

She told the Old Bailey that Silver, the codename for the officer on the ground commanding a surveillance team, told her that his men were confident that they were following Osman. Mr Menezes, who on the morning of July 22, 2005 had emerged from the same Tulse Hill flats under surveillance, was shot seven times in the head with hollow-point “dumdum” bullets after boarding a Tube train at Stockwell.

Ms Dick said: “Firstly, I believed the surveillance team thought it was him. Secondly, from the behaviours that had been described to me, given that I thought they thought it was him, and it very, very well could be him, the behaviours that were described – nervousness, agitation, sending text messages, the phoning, getting on and off the bus – all added up the picture of someone intent on causing an explosion.

“Added to that, this person was coming off the bus and going to the same Tube station that the bomber I had seen on the video had entered the day before, that all added up to someone I thought – I couldn’t be certain – posed a potential and very high risk to the public.”

It is claimed that police had a duty to ensure that the public was not put at risk during its investigation and surveillance. The Met denies failing to discharge a duty under section 3(1) of the Health and Safety at Work Act 1974.

The trial continues.

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