It is generally argued that young offenders should be held accountable for their actions just as adults. Personally, I think treating both young and mature lawbreakers equally is not justifiable as a juvenile is immature but if they do crime which can only be done by an adult then they should be punished as adults.
At the onset, it is better for juvenile criminals to be tried in a different court from that for adults. because children are proven not to have sufficient intellectual or moral capacity to understand the outcomes of their misdeeds. They can be negatively influenced by some bad role models, which should be taken into consideration to give them a fair trial. Else it will be unfair to them to be treated as grown-up people. Moreover, when given a second chance, these underage convicts can have an opportunity to successfully rehabilitate and learn a valuable lesson.
On the other hand, I feel young age should be no deterrent to the way of dealing with criminals if the crime itself seems like it can only be done by a mature person, not by any juvenile. To cite an example, In India, there was a well-known case in which a teenager deliberately raped and murdered a girl brutally, and escaped the death sentence due to being a few months under the responsible age. If these juvenile delinquents were easily pardoned in place of receiving strict punishments as adults, they would not become fully aware of the serious consequences of their crimes which is apparently an injustice to the victims.
In conclusion, the type of crime done by young ones can be valid criteria to decide whether they should be punished as adults or they should be spared from strict punishments.