Irish children as young as five quizzed over sex attacks, drugs and arson
Children as young as five have been questioned by police over serious crimes including sex offences, arson and possessing drugs.
Almost 250 offences by children aged nine and under were investigated by the PSNI in the last three years.
But in every case the suspect walked free because they were too young to be prosecuted.
The law in Northern Ireland states that a child under 10 is below the age of criminal responsibility, and cannot be held accountable.
Some of the crimes, had they been committed by an adult, carry a maximum penalty of life in prison.
Jonathan Craig, a member of the Northern Ireland Policing Board, said he was alarmed.
"We have to accept that no matter the age of an individual, they have the potential to commit the most horrendous crimes," he said.
PSNI statistics show that between January 2013 and December 2015, children aged under 10 were suspected of 237 offences.
24 sex offences;
82 assaults, including assault on police and aggravated assault;
Four arson attacks;
Seven hoax calls;
Two incidents of possessing an offensive weapon;
One case of possessing drugs;
And one threat to kill.
Bizarrely, the list also includes 13 motoring offences. The legal age to drive a car in Northern Ireland is 17.
In one example, a five-year-old child was questioned about criminal damage.
However, none were prosecuted because they were below the age of criminal responsibility.
Children under 10 cannot be arrested or charged with a crime in England, Wales and Northern Ireland.
The age of criminal responsibility is lower in Scotland (eight), but a child cannot be prosecuted until they turn 12.
Mr Craig said that while a child cannot be pursued through the justice system, other consequences are likely.
"It is one thing not being able to take something through the court system in terms of a prosecution," he said. "However, it is certainly a clear indication that there is something fundamentally wrong with the family unit."
Some of the crimes, if committed by adults, could incur substantial prison terms.
Arson can be punishable by a life sentence, depending on the seriousness of the offence.
Other crimes committed by under-10s include burglary, theft, criminal damage and disorderly behaviour.
Justice Minister David Ford has previously called for the age of criminal responsibility to be raised in Northern Ireland.
Mr Ford supports moving it from 10 to 12 - but faces political opposition.
A charity that works with children and young people to reduce crime also backs raising the age of responsibility.
The Northern Ireland Association for the Care and Resettlement of Offenders (Niacro) believes children and young people can be diverted from the criminal justice system through proper support.
Niacro's chief executive Olwen Lyner said children should not be criminalised at an early stage in life.
"We're very concerned that these figures suggest a relatively high number of children are being questioned in relation to criminal activity," she said.
"We know that any involvement with the criminal justice system, even for a minor issue, can have lasting implications for a child and impacts on their future life chances, including their educational outcomes.
"The reality is that most children who offend do so for minor offences and rarely pose a risk of serious harm to others.
"Criminalising children and stigmatising them with a criminal identity at a young age only increases their likelihood of developing more serious offending behaviour as they grow older."
Ms Lyner said early intervention is needed to prevent children ending up in the criminal justice system.
"This is much more cost-effective as it reduces the risk of serious offending and also reduces the costs incurred by the police and courts," she added