Oscar Menjivar-Herrera sexually assaulted two 14-year-old girls and a 12-year-old girl with the help of the 12-year-old boy, who allegedly helped hold the victim down during one of the attacks, according to Nebraska police.
Menjivar-Herrera was arrested in Florida in July 2012, a few months after one of his victims came forward. He escaped from a prisoner transport van in South Dakota while en route to Nebraska for prosecution, and has been on the run ever since.
Police learned Menjivar-Herrera had gone to El Salvador, where he's believed to be from, and authorities believe he may still be there. "I also think, given enough time, he might try to come back to the U.S with a new identity and try to start life over," Deputy U.S. Marshal Shane Knopp told CNN's "The Hunt with John Walsh."
While the attention remains on capturing Menjivar-Herrera, police were shocked when they realized the boy's involvement.
"In all my years I'd never seen such a case where a grown man was using another child to help lure other victims in," said Derek Bees, of the Bellevue, Nebraska, Police Department.
'He was manipulated'
Police said Menjivar-Herrera befriended his victims on social media, telling his victims he was 18. Then he would set up a meeting and tell them he was bringing a 12-year-old boy with him. He made the girls promise that if an adult caught them together, they would say they were actually meeting with the boy.
"Oscar used this 12-year-old boy as kind of his pimp to meet young girls -- 12-to-14-year-old girls," Bees said.
Police say they identified the boy and arrested him for first degree sexual assault of Menjivar-Herrera's third victim. "Unfortunately we just didn't have everything we needed to continue with the court process," said Det. Sarah Spizzirri, of the Omaha Police Department.
As a result, the boy was never charged or prosecuted.
"This 12-year-old boy is street smart," she said. "He's worldly. He's been around and he's been involved in other things. Although he was manipulated by Oscar, he knew what he was doing,"
The boy's demeanor was as if the crime "was a normal thing that occurred and wasn't really that big of a deal," said Bees. "I don't think he understood that it was even wrong."
Children and the 'bystander effect'
Should it be so shocking that police say a 12-year-old has such a total lack of empathy?
As humans, we're all born with some empathy, psychologists believe. Studies show
that newborn infants respond empathetically to the cries of other newborns. And this behavior continues as babies develop. A study of 18-month-old toddlers shows that they demonstrated empathy by spontaneously helping adults pick up things that they dropped.
But as babies grow into children, empathy competes with other forces of human nature, like the so-called "bystander effect."
The phrase bystander effect was coined in the 1960s after people watched or heard a serial killer stalk and stab a woman in two separate attacks in the Queens neighborhood of New York.
This detached mentality can be especially pervasive among youth, who are too young to comprehend what victimization means, Salvatore Didato, an organizational psychologist told CNN in 2009
. When a teenager -- or anyone -- doesn't have a personal bond to the victim, they are less likely to help out.
Experts say sometimes bystanders see the victim as less important than the person committing the crime, who appears to wield power. "The victim to them is a non-person," Didato said.
Schools have started anti-bystander programs to encourage kids to intervene when they see bullying. They're teaching children how to report instances of bullying or other activities where kids may be in danger of getting hurt.
Some programs encourage students to get an even closer perspective on bullying by making friends with bullying victims — which psychologists say could go a long way toward nurturing their sense of empathy.
Of course we have no idea what kind of childhood the 12-year-old boy in the Menjivar-Herrera case may have had that might have affected his sense of empathy. But many psychologists believe
children with traumatic childhoods often come away with damaged empathy.
Child and parenting expert Dr. Michele Borba believes violence in children is learned behavior and, she writes on her website
, it can be unlearned. She supports making early intervention available for aggressive or violent children.
Borba calls on teachers, doctors and others to be more aware of warning signs for violent behavior by children.
Those possible warning signs for violence may include: social isolation, increasing anger, cruel behavior toward pets or other animals, fascination with weapons and depictions of violent behavior in artistic expressions.