Some of the messages are typical of a college-age teenager, talking about doing laundry and playing beer pong. But over time, Tsarnaev’s tweets are also evidence of a transformation.

Northeastern University criminologist James Alan Fox analyzed Tsarnaev’s writings. “You see throughout these tweets a mixture of ordinary activities and partying for example,  yet a growing attachment to Islam, to Chechnya and a dislike and disdain for America,” said Fox.

“What he was doing with his brother, allegedly in terms of preparing to bomb the marathon, was part of his life, not the totality of his life.”