The use of the Old Bailey and other crown courts to try children is "inappropriate", the new head of the Criminal Bar Association has warned.
The Old Bailey is not suitable for trying children, a QC has warned.
Sally O'Neill QC made the comments while calling for a review of the way young people are treated in the criminal justice system.
She said the system was often "poorly adapted" to the needs of children, some of whom can be as young as 10.
Ms O'Neill takes over as chairman of the association on Monday.
The association represents criminal barristers in England and Wales.
In a statement released as she took up the post she called for the government to look at how the system treats children and young people who are witnesses or defendants.
Her comments come after the BBC learned, through Freedom of Information Act requests, that almost 3,000 crimes were committed last year by those under 10.
Ms O'Neill said: "At a time of heightened public concern over youth crime, we need to look again at the way in which the system treats witnesses, victims and defendants, an increasing number of whom are not even teenagers.
"At just 10, we already have a very low age of criminal responsibility in this country. What flows from arrest, interview and the trial process, however, is often poorly adapted to the immaturity of those very young people caught up in the system."
She welcomed new measures brought in to protect young witnesses.
But she said, while young defendants had the same protection in court, outside the court process they were treated differently to young witnesses.
She said: "It is important to remember that, as with adult defendants, not all those charged with a criminal offence are guilty.
"For obvious reasons, these young people are often very vulnerable, whatever we may think of the alleged offence.
"The use, for example, of crown courts such as the Old Bailey to try defendants as young as 10 seems to me to be both inappropriate and outmoded.
"Policy-makers need to look carefully at how the system as a whole, run as it is by adults, treats children and young people on whichever side of the law they find themselves."
Most offences involving children are tried in youth courts but cases where the offence is serious or the co-defendant is adult are sent to crown courts.