A former senior policeman has criticised a "disgraceful" absence of leadership and strategy.
Community leaders say they warned local police about the risk of violence at a meeting, hours before it began.
The Metropolitan Police admits officers were "overwhelmed", but insists the threat they faced was unparalleled.
The violence in Tottenham was sparked by the death of local man Mark Duggan, who was shot by police on Thursday 4 August. His death is under investigation by the Independent Police Complaints Commission (IPCC).
His friends and family, angered by a lack of information from the police, marched to Tottenham police station on the afternoon of Saturday 6 August.
They remained outside for several hours, and frustration grew when no senior officer spoke to them. Violence erupted later that night, when a police car was set on fire, and shops were attacked and looted.
David Gilbertson is a retired Deputy Assistant Commissioner at the Metropolitan Police who served as a senior officer in Haringey Borough, which includes Tottenham.
Having spoken to the police who were on the ground that day, he is very critical of the behaviour of their senior officers.Amateur footage shows clashes between police and protesters near the police station in Tottenham
"There was a disgraceful absence of visible leadership, and that should be shaming for the Metropolitan Police," he told BBC Radio 4's The Report programme.
"With rank comes responsibility, and part of the responsibility is visible command. And secondly, there didn't appear to be a strategy [to deal with the demonstrators].
"It's blindingly obvious to say that you push them away from target-rich environments; a shopping area, a retail park, all of the places that were trashed by the rioters."
Local community leaders also insist the police should have been better prepared.'Spontaneous criminality'
Ken Hinds is a local gang mediator, and family friend of Mark Duggan's girlfriend Simone Wilson. He attended a meeting with the police at lunchtime on Saturday 6 August and says he warned them explicitly about the risk.Continue reading the main story
"The scale and the speed of the violence, the way that car was lit, the way officers were identified very quickly, meant that life became the priority”End Quote Steve Kavanagh Deputy Assistant Commissioner "I told them the word on the street was that Mark was executed by the police, and the family was very upset.
"I also went on to say that if it wasn't handled sensitively, that we could possibly have another riot, another 1985."
That year saw riots around the Broadwater Farm area of Tottenham, after the death of Cynthia Jarrett, an African-Caribbean woman who died from a stroke during a police search of her home. The riots also claimed the life of PC Keith Blakelock.
Stafford Scott also took part in the protest outside the police station, and says he is astonished that senior officers did not make themselves visible.
He is especially critical of Haringey Borough Commander Sandra Looby who went on pre-planned leave on the Friday evening: "This is Tottenham. They [should] know that the following Saturday, we're taking to the streets and we're coming to the police station to demand answers. That's what we've done historically.
"So how the borough commander decided to get on a plane on Friday and leave Tottenham, I do not understand. It beggars belief."
But in her first broadcast interview, Sandra Looby told The Report that that the police received no specific warnings: "We were aware there may be a family or others wishing to come to the police station for a vigil.
"At no point did we receive information that this was going to turn into the spontaneous criminality that subsequently happened."
She rejects the criticism that her decision to go away on pre-arranged leave left the borough under-resourced, pointing out that she handed over control to an officer with a higher rank precisely because of the sensitivity of the situation.
"There was a comprehensive plan put in place for the management of the borough, and I honesty believed [that] actually the shooting was going to be a really long-term issue to manage.
"I provided my strategic plan to an officer more senior to me... and I handed over command to that senior officer at 7pm on the Friday."'Misconception'
She also rebuts the complaint that senior officers should have been out talking to the crowd outside the police station:
"I think once the family arrived at the police station - and they were there a long time - members of my staff tried to engage with the family through community leaders that were outside that police station.
"Obviously we have been unable to directly speak to the family through the IPCC arrangements, and that is very frustrating both for the officers that were there and I'm sure very frustrating for the family."But Deborah Glass, deputy chair of the IPCC, contradicts this interpretation of the rules: "There is some misconception about what happens when the IPCC is involved in an investigation.
"We do have in fact a very clear protocol in place to make it clear that the police are not gagged when the IPCC is involved in an investigation."
Deputy Assistant Commissioner Steve Kavanagh from the Met acknowledges that mistakes were made on the day.
However, he argues the police wanted to avoid being accused of a disproportionately strong response to what began as a peaceful protest.
He backs Sandra Looby's insistence that they could not have prevented what happened: "We didn't have enough numbers there to protect the whole of Tottenham, and yes they became overwhelmed - we've admitted that.
"We've spoken to the chief inspector and the other officers, they have never witnessed such appalling levels of violence directed at them and their community.
"The scale and the speed of the violence, the way that car was lit, the way officers were identified very quickly, meant that life became the priority."
But former policeman David Gilbertson remains convinced that weak policing on that Saturday night led directly to the events across the country: "If you are the person who is in charge of a police operation and you're not being assertive, the message that you're sending is 'well, come along' you might just get away with it, because the police are not going to be assertive. This is a failure of leadership."The Report is on BBC Radio 4 on on Thursday 25 August at 20:00 BST. Listen via the BBC iPlayer or download the programme podcast.