- Published: June 8, 2015
Recently, a news story broke about a teen boy who shot a classmate in cold blood. His immature brain is being used as part of his defense. Brandon McInerny, 14 years-old, shot a gay classmate named Larry King one morning at school. He is being tried as an adult, which has caused quite a stir in the community and brought up questions of accountability for teenagers. Brandon’s lawyers reportedly plan on using a defense centered on neuroscience research, which shows that the teenagers, while they might have a fully-developed body, still lack a fully developed brain[2,3,4]. In the words of the Brandon’s lawyer:
"They [teenagers] should not go away for the rest of their life. The brain development is a physical matter that is beyond your control. If it's out of your control, it lessens your culpability".
I agree that teenagers are fundamentally different from adults, and should be treated accordingly. It is difficult in the case of premeditated murder, however, to argue for significantly lighter sentencing. Any well-adjusted teen knows the moral implications of murder well enough to stop themselves from planning one. Brandon McInerny was not, however, a well-adjusted teen, as he had a difficult home life (and this might be expected of any murderer).
In this sense, I think it is clear that he needs a significant sentence, since he would be likely to commit such crimes even after his teenage brain is fully developed. It is difficult to swallow the thought of someone spending his or her entire life in jail for a crime committed early in high school. However, is it worth the risk to society to lighten their sentence, when at this point, effective rehabilitation isn’t yet possible?
These quandaries are difficult in the case of a possibly very dangerous citizen, but I think other cases of teen violence are much more clear-cut.
For victims of shaken baby syndrome, it is often teen parents who are the perpetrators. In the case of Paul Powell II, he was only 16 when he became frustrated with his daughter’s crying, and shook her, causing death. He is charged with open murder, felony murder and first-degree child abuse.
Teenagers are (correctly) stereotyped to be emotionally labile, erratic, and immature when it comes to making decisions. This has previously been attributed to hormones, inexperience, and lack of analyzing consequences thoroughly. While all of these are contributing factors, evidence in the field of neuroscience reveals that the teenage brain is not functionally mature. Myelination is the process of ensheathing neural cells, and is vital for proper functioning of the nervous system. The human brain is not fully myelinated until the early 20’s, and one of the last areas to myelinate is the frontal lobe. One’s frontal lobe is involved in emotional regulation, planning, impulse control, and risk-assessment among other things. It is clear that without the maturity of this part of the brain, one would be more prone to uncontrolled emotions and impulsivity.
These parents are still children themselves, and often aren’t mature enough to take care of a baby. This could make teen parents much more likely to abuse or neglect their children. The criminal justice system has a vested interest in child abuse because:
“Children who experience child abuse & neglect are 59% more likely to be arrested as a juvenile, 28% more likely to be arrested as an adult, and 30% more likely to commit violent crime.” 
Abused children are also 25% more likely to experience teen pregnancy , and with this in mind, we see that it can become a vicious, self-propagating cycle.
All of this leads me to believe that in the case of teenage parents, there needs to be a form of education which can prevent situations like that of Paul Powell II. These are not always cases of inherently violent people, but usually frustrated, inexperienced, and emotionally unprepared parents. If a 16-year-old needs a license to drive, why shouldn’t she or he need a license to parent?
Maybe a murderer will always be a murderer, but an abusive teenage parent seems like an easier target to reform and prevent.
2. Luna B, Sweeney JA. The emergence of collaborative brain function: FMRI studies of the development of response inhibition. Ann N Y Acad Sci. 2004 Jun;1021:296-309.
3. Paus T. Mapping brain maturation and cognitive development during adolescence. Trends Cogn Sci. 2005 Feb;9(2):60-8.