This case has been described by legal sources as "unprecedented" "complex" and "challenging" and by the judge himself as "unusual".

The law governing how the justice system deals with children who commit offences is laid down in the 2001 Children Act.  

The State is also guided by the "Beijing rules" on the administration of juvenile justice adopted by the UN General Assembly in 1985.

Another influencing factor is the 1999 decision of the European Court of Human Rights in relation to the two boys convicted of the murder of toddler Jamie Bulger in 1993. 

The ECHR found Robert Thompson and Jon Venables, who were both 11 at the time, and tried in public in an adult court, did not get a fair trial.

The Irish legislation does not expressly deal with children who commit the most serious crimes on the statute books. Adults who are convicted of murder are given a mandatory life sentence. 

This does not apply to children, although there is no express ban on a judge imposing a life sentence on a child in the circumstances of a particular case. 

Section 96 of the Children Act sets out some of the principles that apply to the sentencing of children. 

It says any penalty imposed on a child for an offence should cause as little interference as possible with the child's "legitimate activities and pursuits" and should take the least restrictive form that is appropriate in the circumstances.

In particular, it says "a period of detention should be imposed only as a measure of last resort."

The Act sets out the conditions that should apply to children who are detained and interviewed in a garda station. And it directs a child shall not be questioned or asked to make a statement unless they are in the presence of a parent, guardian or another adult, who is not a garda. 

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Identifying a child who is in court facing charges is strictly prohibited. Although an amendment to this section of the legislation states that this provision may be dispensed with if the court is satisfied it is necessary, to avoid injustice to the child, where the child is unlawfully at large or, in the public interest. 

It it likely, however, that anyone seeking the restrictions on identifying a child to be lifted, in the public interest, would have to make out an extremely strong legal case in order to satisfy a judge that it should be done.

Some legal sources say their understanding of the law is that the prohibition on the identification of a child applies for the duration of their childhood and not beyond, meaning they could be identified after they turn 18. 

Hearings are conducted in camera and the only people allowed in court are the lawyers, parents or guardians of the children concerned, people directly concerned in the proceedings and bona fide representatives of the press.

The Act specifies that children under 18 may not be imprisoned.  Instead the court must make an order imposing a period of detention on a child, only if satisfied this is the only suitable way of dealing with him or her.

Normally the period of detention for a child should be no more than three years.

But in the case of those convicted of more serious offences, a longer period of detention can be imposed. This sentence must be served in a children's detention school initially. When the child is 16 they can be transferred to a detention centre and they can be transferred to prison to serve the remainder of their sentence, when they turn 18.

Where a child is found guilty of an offence, the Children Act stipulates that a probation officer's report must be prepared and the child can be remanded for a period of no more than 28 days to allow that to happen. There is provision for an extension of a further 14 days.

The court can also request other medical, psychiatric or psychological reports which would assist it in dealing with the case. 

As such cases are rare, there are not many cases providing a precedent for sentencing children for murder.  In 1998, Mr Justice Paul Carney sentenced a teenage girl to seven years' detention for the murder of chip shop owner Franco Sacco in Templeogue in 1997.  

The girl was 15-years-old at the time of the murder.

The most recent comparable case is that of a 15-year-old boy who was convicted in 2004 of the murder of 14-year-old Darragh Conroy in Laois in 2003.

The boy was named during the trial, due to a loophole which allowed juveniles tried in courts other than the Children's Court to be identified.  

The law has since been amended. 

The boy pleaded not guilty and was convicted by a jury. Mr Justice Barry White sentenced him to be detained for life, for a "premeditated brutal, vicious and callous" killing but ordered that the sentence be reviewed by the Central Criminal Court after ten years.  

The sentence was appealed both by the boy's lawyers and by the DPP, but was upheld by the then Court of Criminal Appeal.  

The appeal court found the trial judge was correct to impose a life sentence subject to review.  

It also found that there was a "special onus" on the court in relation to children convicted of serious offences, which would normally involve lengthy custodial sentences, to have regard to their rehabilitation and welfare for the future. 

The sentence was reviewed in 2014 and the boy was released less than two years later.