Weird news - Young boy (10 years old) charged with murder of third degree murder

In normal murder cases, it is fairly easy to settle matters; in most cases, there is a murder suspect, and there are evidence and other details. In a majority of cases, the judges do not have to do too much, there are not too many ethical dilemma and so on. However, things get difficult when things are not so simple. What happens when the accused is a minor ? In some cases, things are somewhat clearer when the accused is almost an adult (say when the accused is around 16-17 years old) and is accused of a heinous crime - in such cases, the prosecution argues for treating the accused as an adult and the judge also accepts. But what do you do when you have a 10 year old girl ? Such a young girl is not developed enough to be held responsible for her actions, and yet you cannot leave her because of the nature of the crime, where the girl has actually killed a toddler (link to article):

A 10-year-old girl has been charged with murder after allegedly violently shaking a baby boy and throwing him into a crib.
The fifth-grader, from Pennsylvania, was charged on Friday after an inquest into the death of 11-month-old Heath Conrad Ryder, who died of a traumatic brain injury at Hershey Medical Center in August last year.
The baby boy was at day care when the alleged assault happened a few months earlier. His mother, Shelly Ryder, came to pick him up and found him 'limp and lifeless'.
The young girl, who has no history of behavioural problems, will be tried as a juvenile and has been released into the custody of her parents until the next hearing later this month on condition that she does not have unsupervised contact with children under five.