leaving the white house. See shortly. But first fast-moving developments this is boylston street in boston. It looked like a war zone as the bombs burst. This was the image today, finally back open.... See More
leaving the white house. See shortly. But first fast-moving developments this is boylston street in boston. It looked like a war zone as the bombs burst. This was the image today, finally back open. This evening resilient bostonians proving their city's strength. Tonight what we did not know about the two brother, during the carjacking and the shoot-out with police. Abc's dan harris with his hometown of boston. Dan, good evening. Reporter: Good evening to you. What was once a massive crime seen in the heart of the city is now, as you can see, bursting with life once again. This, as we learn more about the brothers at the heart of this story -- and surprising revelations about the events leading up to the end of this city's nightmare. Tonight, new pictures taken on the night when the brothers tsarnaev eajedly engaged in a gunfight with police. That is them, says the local resident who took these shots from his bedroom window, firing from behind their carjacked black mercedes suv. And remarkably -- tonight, abc news has learned that police believe during this whole shootout, that the semiautomatic handgun in tamerlan's hand was the only gun the brothers had. That gun was later recovered at the scene of the shootout in watertown, which means that all day friday -- as the city of boston was shut down, the man holding it hostage, justifiably considered armed and dangerous, was at least as far as police can tell right now, actually an unarmed 19-year-old, kurld up and bleeding in the back of a boat. Tonight we are getting new clues in the mystery of that young man. How did a boy like dzhokhar seen here dancing a robot and wrestling good naturedly with a friend, turn into this? The person who allegedly carried a bomb in his backpack into a crowd of innocents? Reporter: Auto mechanic gilberto junior said his friend jahar was always chatty and -- dzhokhar was always chatty and fun, except when his big brother was around. He was very quiet. He didn't say a word next to his brother. Reporter: Tamerlan, we're learning more about him too. This is his mug shot from when he was arrested for allegedly slapping his girlfriend in 2009. Despite the flashy exterior, he and his wife and three-year-old daughter were actually intermittently on welfare, as recently as last year. Today, focus turned to a friend of tamerlan's known old as misha, described as a muslim convert, a bald, heavy-set man with a red beard. Tamerlan's uncle tells abc news that under misha's influence, tamerlan became increasingly militant. In russia today, tamerlan's mother called that idea nonsense. And one more note on this notion at the brothers only had one gun on that fateful thursday night into friday mornin police stress tonight that they are still investigating and hoping to confirm that finally. Also, one more note on the older brother tamerlan he is still in a boston city morgue. As of yet, nobody has stepped forward to claim his body. David? Sure is great to see all those people behind you on boylston street.
This transcript has been automatically generated and may not be 100% accurate.