The Metropolitan Police will apologise to those wrongly arrested during the coronation if it is found officers made mistakes.
A review is being carried out of the massive security operation which included the arrest of six anti-monarchy protesters and three charity volunteers who were all later released without charge.
Assistant Commissioner Louisa Rolfe told the London Assembly Police and Crime Committee on Wednesday: “We want to understand the detail of what happened, and those individual arrests and the circumstances surrounding them will be fully explored in our debrief process.
“If we’ve got things wrong, we will apologise to individuals affected and we’ll work through that.
“But also we trust our officers to make decisions on the ground, often with the circumstances they face and on the basis of information and intelligence available to them.
“They will make inquiries to validate the information they hold but also they will sometimes need to make very fast time decisions to ensure that they’re carrying out their duties to ensure the safety and security of an event.”
Ms Rolfe agreed the force took a more cautious approach by having a “lower threshold” for allowing protests on the day.
She went on: “We were very clear in policing the operation that we must consider balancing people’s human rights with the heightened security context that are facing the numbers of public attending this occasion.
“And, therefore, our threshold and tolerance for disruption might have been lower than if we were dealing with other events.
“But we were very clear that we were not banning protests and, in fact, there were a number, a significant number, of people involved in protest – peaceful protests – throughout the coronation event.”
She and Deputy Assistant Commissioner Ade Adelekan defended the quality of “intelligence” that led to the arrests.
Six members of anti-monarchy organisation Republic were arrested on suspicion of going equipped to lock on – something some protesters do to make them more difficult to move from sites – because they had luggage straps to secure placards in their lorry.
Three volunteers for women’s safety scheme Night Stars were also arrested in possession of rape alarms, which they carry to give out as part of anti-spiking kits.
Ms Rolfe said: “The way that we work and we operate is that we have to respond swiftly to a developing intelligence picture and it may not always be feasible or practical to ensure evidence before an arrest is made.”
Mr Adelekan told the London Assembly committee: “The intelligence was significant enough and worried us enough that senior colleagues were briefed late on the Friday night into the Saturday, and I suggest that senior political colleagues were briefed on some of the details of the intelligence.”
He said officers were “deeply concerned” for the safety of the public lining the procession route and that they had worked through the night before the coronation.
He added that the fact that protesters managed to get on to the procession route for the late Queen’s Platinum Jubilee parade had increased concerns around the coronation.
Deputy mayor of London Sophie Linden said: “I know that the Metropolitan Police are undertaking a review of the overall operation in the police on that day, which will also include those arrests.
“We’re looking forward to the outcome of that review and being able to assess and assure ourselves around that review, and the Mayor has also asked that the high-level conclusions of that review are made public.
“Because it’s really important in terms of transparency and accountability that, where there is that public interest concern, that the public can see what the review has come up with and, if lessons need to be learned, they are learned.”
Graham Smith from the anti-monarchy group Republic said: “They continue to defend what was palpably an unlawful arrest of eight peaceful protesters. They continue to suggest that the nature of the event gave them lawful grounds to have a lower tolerance of such protest.
“Until they understand what they did wrong, and until there is significant and sincere redress for their actions, we cannot trust the police not to behave in the same manner again.
“It should not take a lengthy inquiry to know the Met Police got it badly wrong. While we welcome the undertaking to apologise, their statements to date raise doubts about their sincerity.”