Questions have been raised about the way children are dealt with by the criminal justice system after two young boys were convicted of attempted rape.
Michele Elliott, of charity Kidscape, said the decision to try them at the Old Bailey was "absolutely wrong".
The NSPCC also raised concerns that the eight-year-old victim was too young to cope with cross-examination.
The boys have been placed on the sex offenders register ahead of sentencing later. Both were cleared of rape.
The girl had alleged she was raped in a field near her west London home in October 2009.
The boys, who were both 10 at the time and cannot be named, had each denied two charges of rape and two of attempted rape of a child under 13.
The BBC's home affairs correspondent Danny Shaw said attempts were made to make the court environment less intimidating for the defendants.
The judge and barristers removed their wigs and gowns, and the boys were allowed to sit alongside their mothers in the well of the courtroom rather than the dock, but despite this they often appeared bewildered, our correspondent added.
Former director of public prosecutions Sir Ken MacDonald, writing in the Times, said the trial had been "a spectacle that has no place in an intelligent society".
He added: "Very young children do not belong in adult criminal courts. They rarely belong in criminal courts at all."
But Metropolitan Police commissioner Sir Paul Stephenson refused to criticise the decision to bring the trial to court.
He said: "I do not criticise the decision to bring it, it is a tough call.
"To see two young kids on trial for heinous offences against a younger child is something that gets to all of us as members of society."
Kidscape's director Ms Elliott said it was "absurd" to try the boys in "an adversarial court situation".
"I think it reflects horribly on our whole system, that a case like this with children should be tried in this way.
"It should have been held in camera with no publicity at all. The whole thing is horrific."
"In camera" is a legal term for cases which are held in a judge's private chambers, from which the press and public are excluded.
NSPCC lawyer Barbara Esam said children often struggled to cope with cross-examination, and in particular, with leading questions, used by barristers to steer those being quizzed.
"Children find these very difficult to deal with, particularly what we call 'tag questions', where you say, 'You went to his house, didn't you?'
"A child finds that difficult to not answer 'yes'."
She said pre-recorded interviews, rather than live cross-examination, should be used where children are required to give evidence in court.
Paul Mendelle of the Criminal Bar Association, agreed: "We have to avoid things like tag questions - 'You weren't in the park that day, were you?' - that combination of positive and negative statements can be confusing for children.
"If an adult is saying to a very young child something didn't happen, the child may be very conflicted by that because it's used to obeying adults."
Felicity Gerry, a barrister and author of the Sexual Offences Handbook, highlighted the differences between this and other cases.
"A lot of children may know that to kill a three-year-old with an iron bar or to drop concrete on a child is wrong, but proper sexual awareness only comes with greater maturity."
'Lessons to learn'
If the boys had been younger than 10 - the age of criminal responsibility in England and Wales - they would have been too young to be charged.
As he ordered them to sign the sex offenders register, the judge Mr Justice Saunders said: "I am not quite sure how it applies to children of this age."
Speaking about the trial after the verdict was delivered, he added: "I will at some stage be sending my views about the procedure to those who are most concerned with it.
"That is not to indicate that there is anything wrong, but we should do everything we can to improve how we deal with these things by looking at the lessons that we can learn."
Alison Saunders, chief Crown prosecutor for London, defended the decision to go ahead with the trial.
"Any case involving young children is always difficult and calls for the most sensitive handling," she said.
"The CPS was determined that these young defendants should have a fair trial and every effort was made to that end."