By Nick Assinder
BBC News website political correspondent
There was no confrontation, no angry words, no emotional outbursts.
When Met police chief Sir Ian Blair came face to face for the first time with members of Jean Charles de Menezes' family it was in the relatively calm, formal surroundings of the Boothroyd Room of parliament's Portcullis House.
Sir Ian offered personal apology
The small group joined members of the public and media to sit just a few feet behind Sir Ian as he paused proceedings of the home affairs committee of MPs to again apologise for the shooting.
Expressing his sorrow and offering condolences, Sir Ian said he and his force were determined to learn lessons from the tragedy.
He then sent a message offering to speak to the family afterwards to apologise personally for Mr Menezes's death.
A Scotland Yard spokeswoman said: "That was politely declined and was relayed to the Commissioner by the family liaison officer."
There may have been no confrontation, but neither was there any sign that the anger and bitterness has subsided.
Once again, Sir Ian found himself attempting to express the impossible position he believes his officers were in when they believed they were dealing with a suicide bomber.
Mr Menezes was shot a day after the failed London bombings
"What do you do?" he asked. If officers had witnessed a suspected bomber boarding the London bus blown up on 7 July: "I don't know what you do. Thirteen people died in that bus," he said.
All the while he was talking his hands wound themselves around each other and his ankles crossed under his green Commons chair.
So, he confirmed, there had been no significant change to the rules covering the use of lethal force in the wake of the shooting.
It had been reviewed immediately afterwards and a few minor administrative changes had been made. But the policy stands.
It is a policy that Home Secretary Charles Clarke had earlier insisted should not be branded "shoot to kill" or even, he pleaded, "shoot to protect".
Police officers' only aim was to save lives, he insisted.
The explanation gave little comfort to members of Mr Menezes' family who later expressed their horror that the policy was still in operation.
Clarke resisted shoot to kill label
But perhaps there was one statement from Sir Ian that might help at least explain how such a tragedy could have happened.
The police chief said it had always been the accepted wisdom that the policy on lethal force should not be discussed openly.
That, he said, must change. The events surrounding 7 July bombings and the shooting of Mr Menezes represented a watershed.
"I think now we have to find a process for debating these issues without necessarily revealing the absolute detail of the tactics, which would be extremely unhelpful," he said.
It was a difficult committee session with much of the debate constrained by ongoing legal actions and inquiries.
And, ultimately, it probably did little to help explain the terrible events of 7 and 21 July or the shooting of Mr Menezes.