Brown and his father reportedly used to practice shooting behind their western Pennsylvania farmhouse. The 11-year-old had received a shotgun as a gift for Christmas from his father and was a good shot, winning a turkey shoot just weeks before the shooting, beating out several adults.
The alleged murder followed another incident in Arizona, when a 9-year-old boy accused of shooting his father and his father's roommate pleaded guilty to negligent homicide.
"What springs up in these cases is poor impulse control, a degree of frustration and alienation and probably a high degree of disempowerment, feeling out of control and having to do something to control the situation," said Nieburg.
These baby-faced defendants are presumed innocent until proven guilty, but cases like these beg the question: Why do kids kill?
"If a kid is psychotic, hallucinating or delusional, they may think something has happened, like aliens invading or the person killed is doing something to them," he said.
"The key is you have to look at three things: the biological, the psychological and the socio-cultural," said Nieburg.
Biological factors can include brain damage, head trauma and lower intellectual and emotional functioning, as well as drugs, alcohol and even fetal alcohol syndrome.
Social factors like "how you grew up" and social messages can also be influences: "If you were born in the 'hood' as opposed to upper Fifth Avenue, even your religious beliefs," he said.
The family environment can also play a role in why some children are able to kill.
"If there is violence in the home there is a certain risk factor," said Murray Straus, co-director of the Family Research Lab at University of New Hampshire.
"The usual result is kids doing more hitting of other kids in the family and other unrelated kids, as well as attacks on their parents," he told ABCNews.com. "The single biggest predictor of when kids hit parents is how much the parents are hitting the child under the euphemism of spanking."
Some experts even suggest that watching violence on television and in video games promotes aggression in children, although that research is controversial.
Lt. Col. Dave Grossman, a West Point military psychologist who trains health professionals on how to prevent killing, contends violent programs desensitize children to violence.
With Gloria DeGaetano, a former police officer, he wrote the 1999 book, "Stop Teaching Our Kids to Kill."
"I predicted that we would soon see more 12-year-olds committing unspeakable crimes like mass murder," writes DeGaetano.
"Sensational visual images showing hurting as powerful and domination of others as permissible are dangerous."
But psychologists are confounded by why some children cross the line and kill. Why is one child exposed to violence propelled to kill and another is not?
"The critical issue is all these factors only affect the person at risk," said criminal psychologist Nieburg. "A lot of kids watch programs about suicide, but they don't do that. Certain kids are just predisposed to violence."