He said this during the photo shoot with Hirn: "I don't have a single American friend. I don't understand them."
And in 2009, Tamerlan, then 22, was arrested for domestic assault and battery after allegedly assaulting his girlfriend, according to Cambridge Police records cited by the website spotcrime.com.
'I cried ... when they named him'
Dzhokar, however, apparently did have several friends. Torrie Martinez, 20, was one of them.
Friday, Martinez stood on Cambridge Street looking down Norfolk Street where the Tsarnaev brothers made their home. Martinez used to catch the city bus with Dzhokar every day to school and was on the wrestling team with him.
"I wish I could say he was a bad kid," said Martinez, still trying to absorb the news. "But he was a nice kid from what I knew of him. I talked with him on a daily basis. I practiced with him."
He was a sophomore when he met Dzhokar, who was a year behind him. They talked about stuff high school boys talk about; it never got too personal. Martinez didn't know Dzhokar was Chechen.
And they talked wrestling. "He was a smaller kid, but he did well for his weight class," Martinez said.
A smile appears beneath his scruffy, unshaven face.
"Between me and him, I would pin him."
Now he wished he'd whupped him a little harder. The smile vanishes from Martinez's face.
"I cried ... when they named him."
It will be hard to trust anyone again.
Larry Aaronson, a former teacher at Cambridge Rindge & Latin, said he had taken pictures of Dzhokar wrestling.
"There is nothing in his character, in his deportment, in his demeanor that would suggest anything remotely capable of any of these things that he is now suspected of doing," Aaronson said.
"He was so grateful to be here, he was so grateful to be at the school," he said. "He was compassionate, he was caring, he was jovial."
He described Dzhokar, whom he saw in the neighborhood nestled between Harvard and MIT a few weeks ago, as "a lovely, lovely kid."
Construction worker Joey Barbaso, 50, has lived in the neighborhood since he was 5. His pants are worn from hard work and stained from years of paint. That's the kind of people who live here -- along with college students.
"It's just, I dunno," he said. "You never know who you're living next to."
Robin Young, host of radio's "Here and Now," said Dzhokar was her nephew's best friend. She called him a beautiful boy.
But now he was a man despised by all of America.
Tweeting even after the bombings
Dzhokar had been more public with his life than his brother. More people stepped forward Friday with accounts of their relationships with him than they did about Tamerlan.
Dzhokar had a page on the Russian equivalent of Facebook on which he described his worldview as Islam.
He was active on Twitter and showed a certain amount of brazenness by continuing to tweet in the aftermath of the bombing.
"Ain't no love in the heart of the city. Stay safe people," he tweeted just hours after the bombings.
Tuesday, he called "fake" a story about a woman who died in Monday's bombings and was found by her boyfriend who was planning to propose.
He responded to someone else's tweet in a conversation about the victims: "Lol those people are cooked."
His friend, Giovanni, who only wanted his first name used, said Dzhokar was even joking on Twitter about "how he had like a dream about eating a cheeseburger and then he was like, 'And the next day, what did I have next?'
"And I responded (on Twitter) in a joking way, 'A hot dog?'
"And here I am, like, having a conversation with this guy not knowing what he was doing or what he did."
Giovanni said he played video games with Dzhokar, but hadn't seen him in person since January. He said his friend had told him he was engaged to be married, even showing him a photo of his supposed fiancée on his phone.
"He was always just quiet, quiet in a nice (way)," Giovanni said. "You just wouldn't suspect that he'd do something so messed up."
And he said Dzhokar was particular about his identity.
"He used to tell us he's the only Chechens ... we'd ever come across," Giovanni said. "Sometimes they'd call him Russian and he'd always correct me."
He said he didn't know much about Tamerlan; only that Dzhokar had said his older brother was a boxer.
"A year ago when I met him ... to think. I had no idea I'd be friending such a messed up person. You just think, 'Oh, he seems nice, he seems innocent.'"
Dzhokar worked for a time as a lifeguard at a pool at Harvard University, said George McMasters, who hired him about 2½ years ago.
McMasters was impressed with Dzhokar's work ethic.
"He showed up on time, he watched the water, he rotated from position to position fine, got along well with others."