“Often at that age, people do things inconsistent with what they know to be right or wrong ... [and] they show especially poor judgment when they are with their peers,” says Laurence Steinberg, a psychology professor at Temple University in Philadelphia. He’s not surprised the allegations include, for instance, that they collectively decided to throw out the backpack after discovering it contained fireworks that had been emptied of gunpowder.
Research has shown that when adolescents are with their peers, they “pay a disproportionate amount of attention to the potential rewards of a decision and not to the cost,” Professor Steinberg says. Often, he says, they don’t believe they’ll be caught, or they aren’t thinking about what the consequences could be if they are.
An FBI affidavit says that the three friends, who at one point were all students at the University of Massachusetts – Dartmouth, had seen images of Mr. Tsarnaev as a suspect in the bombing, had texted with him, and then put the backpack in the garbage “because they did not want Tsarnaev to get into trouble.” It does not specify what happened to the laptop. The FBI account also says Messrs. Kadyrbayev and Tazhayakov had heard Tsarnaev say a month before that he knew how to make a bomb.
The three suspects’ lawyers have denied the charges and said the young men didn’t know that their friend was one of the bomb suspects.