The families of those who died on 11 September thought they could not possibly feel any more pain.

That was before the release of the videotape showing Osama Bin Laden expressing pleasure that the attacks on America had gone even better than he hoped.

After seeing that tape, I have never hated anyone more, I hate him and all that he stands for

Brother of victim

On the tape he is heard saying that he had not anticipated the Twin Towers would collapse, killing so many people.

In New York, still grieving over the loss of 3,000 people at the World Trade Center, the words prompted disgust and revulsion.

The release of the tape had been anticipated for a day or two, and Americans were waiting to see what was described as the final proof of Bin Laden's guilt.

Patrick Cartier lost his brother in the attacks

In Times Square, people stopped in the street to watch the broadcast on television screens that usually convey information about the financial markets.

There were similar scenes in offices and department stores across Manhattan. For the most part, the broadcast was watched in silent anger.

Some relatives of people who died in the attacks said later that while they recognised the importance of the tape, they could not bring themselves to watch it.

One who did view it was Patrick Cartier, whose 26-year-old brother James was killed when the Twin Towers collapsed.

"If this tape does not convince every nation that Osama Bin Laden is the perpetrator of evil, then nothing will," he told BBC News Online.

"He sent his own people to die in the attacks on America, and he didn't even tell them," he said, adding, "After seeing that tape, I have never hated anyone more. I hate him and all that he stands for."

Justification

President George W Bush revealed that he was hesitant about authorising the release of the tape because he knew it would be a vivid reminder to many people of their loss.

Rabbi Potasnik said people cannot fully fathom Bin Laden's madness

But he also knew it would be "a devastating declaration" of Bin Laden's guilt.

"We're going to get him," said Mr Bush. "Dead or alive, it doesn't matter to me."

The president's justification for releasing the tape seems to have been accepted by most Americans.

They accept their government's assertion that it is compelling evidence of Bin Laden's guilt, and a demonstration to the rest of the world of the need to support the "war against terrorism".

Undoubted authenticity

Rabbi Joseph Potasnik, the Jewish chaplain to New York's fire department, said the tape was a re-confirmation of where responsibility lay for the attacks on 11 September.

"We have seen Middle Eastern groups cheering as blood was spilling," he told BBC News Online.

"I do not think any of us can fully fathom the maniacal madness of a person who can rejoice at the savage slaughter of human beings," he said.

Mark Dean believes the tape is genuine

But on the streets of New York today, there were still a few lingering doubts about the authenticity of the tape.

Pam, visiting the city from Texas, said the tape could be a smoking gun that would change views in the Islamic world. But she went on:

"I still have doubts about the tape's validity. You just don't know who is telling the truth. People are saying there can be different translations of Arabic, so I am fairly sceptical."

Mark Dean, a streaming video director from San Francisco, said he did not always believe the US Government, but thought the tape was probably genuine.

"If it is real, it is astonishing that this guy shows no concern for the thousands of people he condemned to die," he told BBC News Online, adding, "To be so blas� about it is unbelievable."

Geri Schwartz, a college lecturer from Long Island, had absolutely no doubts about the authenticity of the tape.

"I think it is disgusting," she said, adding, "It makes you sick just to hear him. I hate him... it was like he was gloating."

"I think we have to get Bin Laden and all the terrorist groups associated with him. If we don't, then in time they will start up again," she said.