More than 1,000 children in Northern Ireland have received criminal convictions in the last five years, BBC News NI can reveal.
The youngest criminals convicted in that period were just 12 years old.
It costs £324,000 per year to keep a young person in custody and NI's young offender population is proportionately larger than that of England and Wales.
Now the NI Children's Commissioner has called for the age of criminal responsibility to be raised to 14.
Figures obtained by the BBC under Freedom of Information show that 101 children have been convicted of one or more crimes so far this year.
The PSNI says it is committed to engaging with young people to create a "safe, confident and peaceful society".
In total, 1,085 children under 18 carried out one or more crimes in the last five years.
Among that number are five 12-year-olds, the youngest of whom was convicted of criminal damage.
The highest year for convictions was 279 in 2015, compared to 207 in 2017.
"Clearly the figures indicate that from time to time young people will come to our attention as potential offenders," said Supt David Beck.
"In these circumstances, we endeavour to ensure that young people enter custody for the right reasons at the right time and that we explore other options outside of police custody for the protection of everyone.
"It is important that young people are not criminalised for behaviour which can be dealt with more appropriately by other means.
"It is always encouraging to see the level of crime reducing year on year, and the figures shown are a good example of this downward trend."
In England and Wales, there were 25,700 10 to 17-year-olds sentenced in all courts in the year ending March 2017, according to the latest statistics available.
However, fewer children reoffend in Northern Ireland.
But comparing differences in other jurisdictions in the UK is difficult, due to different legal systems.
A report by the Audit Office last year revealed that it costs £324,000 per year to keep a young person in custody.
The Department of Justice said it has made "significant change and improvement" to Northern Ireland's youth justice system in recent years.
"Evidence shows that the best means by which the risk of future offending can be reduced is to intervene early and support children to change behaviours before they become embedded," the DoJ said in a statement.
"It is also the best way to prevent individuals and communities from becoming the victims of crime."
The age of criminal responsibility - when a child is considered capable of committing a crime and old enough to stand trial and be convicted of an offence - is currently set at 10 in Northern Ireland, England and Wales.
The age of criminal prosecution in Scotland was raised to 12 in 2011, meaning younger children would be sent to children's hearings instead of court.
In March, a bill was published to raise the minimum age of criminal responsibility in Scotland from eight - the lowest in Europe - to 12.
It means no child under 12 will receive a criminal record.
Custody for young people in Northern Ireland is provided at the Woodlands Juvenile Justice Centre in Bangor, County Down.
Woodlands can house 48 boys and girls between the ages of 10 and 17.
In June, inspectors said the facility is "the envy of similar establishments in England and Wales".
But they expressed concern that 76% of children sent there are from a Catholic background.
'Exploited and goaded'
In July, during some of the worst violence witnessed in Londonderry in recent years, petrol bombs were thrown into the Fountain estate in July and police came under serious attack with petrol bombs and gunshots in the Bogside.
The PSNI said children as young as eight were involved and accused dissident republicans of being behind the attacks.
"In many cases it would appear that young people are being exploited and goaded into criminal activity by adults who have nothing to offer their communities," said Secretary of State Karen Bradley.
Northern Ireland Children's Commissioner Koulla Yiasouma said: "The evidence continues to indicate that it is our most vulnerable young people who are involved in crime, with early community-based intervention often being the best way to ensure they do not offend or reoffend, and thereby keep our communities safe.
"I am deeply concerned that children as young as 12 are included, and is why I am calling for the age of criminal responsibility to be immediately raised to 14, to enable services to more effectively intervene."