Teacher: Bombing Suspect Had 'Heart Of Gold'

So who is Dzhokhar Tsarnaev, the 19-year-old who authorities say is the second suspect, armed and dangerous and still on the run?

Larry Aaronson was a teacher at Cambridge Rindge and Latin School, the public high school in Cambridge, Mass. attended by Tsarnaev (and our host Robin Young's nephew).  Aaronson also lived in the same neighborhood as Tsarnaev.

"I'm shocked. I'm utterly shocked," Aaronson told Here & Now. "He had a heart of gold, he was a sweetheart, he was gracious, he was caring, he was compassionate."

Aaronson, who is now retired, also lived about three houses down from Tsarnaev. He recalls talking with Tsarnaev about being "born in a war zone" in Chechnya. Tsarnaev told him he was lucky to get out, Aaronson said.

"He was athletic, he was a good student," Aaronson said. "This comes as a total shock and it's totally unexpected."