At one point, Tamerlan Tsarnaev, the alleged Boston Marathon bomber who was killed late Thursday or early Friday morning, was an aspiring boxer who said "I like the USA" after a successful bout and spoke of boxing for the U.S. Olympic team.
According to the Lowell Sun, Tsarnaev, who came to the U.S. from Chechnya in 2003, won a Golden Gloves novice fight at the 178-pound weight division in January 2004.
"I wanted to fight in the Gloves to see how I would do," Tsarnaev said at the time, according to the Sun. "So far, so good."
He added, according to the Sun: "I like the USA ... America has a lot of jobs. That's something Russia doesn't have. You have a chance to make money here if you are willing to work."
Tsarnaev continued his boxing career. According to multiple media reports, he took part in a number of regional bouts and, according to the Sun, won the prestigious Rocky Marciano trophy as the New England heavyweight champ a number of years later.
According to reports, he was studying engineering at Bunker Hill Community College in Boston but took a leave of absence to train for the Golden Gloves Tournament of Champions in Salt Lake City in 2009.
According to the official website of the Golden Gloves, Tsarnaev did participate in the 201-pound division in 2009 but lost a decision to Lamar Fenner of Chicago.
In a photo essay leading up to the Golden Gloves bouts, he said he thought he could use boxing to earn American citizenship, going so far as to say he thought he could make the U.S. Olympic team.
In the same essay, however, he hinted that he wasn't completely comfortable in the U.S., saying, "I don't have a single American friend, I don't understand them."
What happened in the intervening years has not yet been revealed.
Super middleweight contender Edwin Rodriguez wrote on his Facebook page that he sparred with Tsarnaev two years ago.
"Two years ago I sparred this oddly dressed Russian at Camp Get Right here in Worcester," Rodriguez wrote. "Today I find out he's a terrorist and one of the Boston Marathon bombers. I'm glad I put a beating on him, but wish I'd known he was evil, because I wouldn't have slowed down on him and would've knocked his ass out.
Tom Lee, president of the South Boston Boxing Club, didn't see a person capable of the carnage that was perpetrated at the marathon Monday and on Thursday night. He said Tsarnaev trained off and on at his gym in 2010 and said he was a "gifted athlete" who "could win national titles and be an excellent professional."
Lee said Tsarnaev wasn't a member of the gym, and didn't build any strong relationships with the coaches or fighters there. Mostly he worked with coach John Curran, but when Curran was busy, Lee would work with him.
"Some of these kids I have really close relationships with," Lee said. "This guy is not one of them. Neither John or I had that kind of relationship with him."
Lee added that Tsarnaev didn't cause any trouble at the gym when he was there, but he also wasn't as dedicated as other fighters.
"He was one of those guys who could kind of train half-ass and still be good because he was naturally gifted," Lee said.
Lee said he found out that Tsarnaev was a suspect in the bombing when a fighter from his gym texted him early Friday.
"I thought he was kidding me," Lee said. "I said 'Oh, ha ha, funny.' Then he said he was serious."
Lee turned on the TV, and that's when it really hit him.
"I had a knot in my stomach and almost puked," he said. "I couldn't believe it. I was absolutely horrified when I saw it."
Tsarnaev, 26, and his brother Dzhokhar Tsarnaev, 19, have been the prime suspects in the Boston Marathon bombings that killed three and wounded more than 180. Late Thursday night, they allegedly shot to death an MIT police officer and hurled explosives at police in a car chase and gun battle that left Tamerlan Tsarnaev dead, according to authorities.
Dzhokhar Tsarnaev was also an athlete in the U.S. He attended Cambridge Rindge and Latin School in Cambridge, Mass., where he competed on the wrestling team. In 2011, he was named a Greater Boston League Winter All-Star, according to multiple reports.
He earned a $2,500 college scholarship from Cambridge in 2011 and was reportedly a student at UMass-Dartmouth.
Information from ESPNBoston.com's Jack McCluskey was used in this report.