A Twitter account purportedly belonging to Dzhokhar Tsarnaev, the second suspect accused of the Boston marathon bombings, was last used two days after the crime was committed.
Tsarnaey, who was known as Johar to his friends, tweeted: "Ain't no love in the heart of the city, stay safe people."
His final tweet from the account read:
"I would confirm this as to being his twitter account. Those users went to my high school," Stefanie Gardner, of the Rindge Class of 2011, told Buzzfeed.
A social media profile on Russian 'Facebook' site VKontakte lists him as Djohar Tsarnaev, living in Boston. He is listed as having attended school in Makhachkala, in the Republic of Dagestan, between 1999 and 2001, and went to high school at Cambridge Ringe & Latin School, whose alumni include Matt Damon and Ben Affleck.
Many of the tweets feature rap lyrics, littered with profanities, and there are references to smoking weed and the sexually explicit TV show 'Game Of Thrones' - ostensibly, not the tweets of an especially religious Muslim.
He does mention his religion, and has retweeted several imams.
But he also seems keen to stress that there is no connection between Islam and terrorism, taking to Twitter to say:
Liana Woskie told HuffPost that she went to the Cambridge Rindge & Latin School with his elder brother Tamerlan and was in his high school graduating class of '06. He was on the volleyball team, she said.
"I think this is a huge shock in the Cambridge community," Woskie said. "This is nothing that anyone expected."
Tamerlan died in an overnight shootout with police, but officials are still searching for Dzhokhar.
Woskie's younger sister graduated with Dzhokhar in 2011, Woskie said. "The younger brother acted as a lifeguard, was a scholar athlete, would be a designated driver to his friends," adding: "He was a compassionate human being."
Most of Dzokhar's tweets deal with the mundane everyday life of a young medical student, being late for class, having long breakfasts and chasing girls.
Many of his friends have expressed shock and distress that their classmate was linked to the Boston bombings, with several claiming they do not believe he committed the atrocity.