BOSTON—New details emerged Sunday of the accused marathon bombers' alleged theft of a sport-utility vehicle before a chaotic gunfight in the city's suburbs. 
 
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 About 40 minutes after they allegedly shot and killed a Massachusetts Institute of Technology police officer in Cambridge, Mass., Tamerlan and Dzhokhar Tsarnaev, the brothers accused of the bombing, crossed the Charles River into Boston and stole a Mercedes SUV at gunpoint, briefly holding the driver hostage, according to an excerpt from the Cambridge Police Department report filed by the driver and reviewed by The Wall Street Journal. The alleged carjacking occurred at about 11 p.m. in Boston's Brighton neighborhood on Brighton Avenue, said the excerpt, which didn't name the victim. 
 
 According to the report, one of the brothers jumped out of a Honda Civic and reached in through the front passenger side window of the SUV, opened the door and pointed a silver colored semi-automatic pistol at the driver. 
 
 The gunman then ordered him to drive to Watertown and was followed by the Honda, the report said. 
 
 Once in Watertown, the victim was ordered to slide over to the passenger side, the report said. The two brothers then removed luggage from the Honda and loaded it into the trunk of the Mercedes, the report said. 
 
 From there, one of the brothers drove the Mercedes while the second sat behind the victim, the report said. 
 
 The victim told police he was driven to a Shell Gas Station on Memorial Drive in Watertown. Inside the car, the brothers "declared to [the victim] that they were the Boston Marathon bombers and would not kill him because he wasn't American," the report said. 
 
 When the victim saw an opportunity to flee, he ran to a nearby gas station where he asked the owner to call 911, the report said. 
 
 Tamerlan Tsarnaev was killed in a shootout with police in Watertown early on Friday morning. A 20-hour manhunt resulted in Dzhokhar Tsarnaev's arrest that night. ||||| The two brothers suspected of bombing the Boston Marathon’s finish line told the man they carjacked on Thursday night that they only decided not to kill him because he “wasn’t an American,” according to a report Monday. 
 
 NBC’s Pete Williams said the man, who asked not to be identified, told police that Dzhokhar and Tamerlan Tsarnaev said they spared his life because he was not an American. 
 
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 “He also told the police investigators after this episode, when they finally got to him — he is the one who called 911 — that they let him out of the car and didn’t kill him because he wasn’t an American,” Williams said. 
 
 (Also on POLITICO: Report: Suspects not licensed for guns) 
 
 Williams said NBC had exchanged e-mails with the victim, who described the suspects as “brutal but cautious.” He said the victims didn’t want to appear on camera. 
 
 Meanwhile, a senior United States official told The New York Times that the Tsarnaev brothers may have been headed to New York City in the Mercedes-Benz SUV they hijacked Thursday, although it’s not clear if they planned on further attacks there. 
 
 Williams said on MSNBC’s “Morning Joe” that the carjacking victim had heard the suspects - who were speaking in a foreign language - use the word “Manhattan.” 
 
 “He told the police that he couldn’t understand what they were saying but that he thought it was, quote, blah, blah, blah, blah, Manhattan blah, blah, blah,” Williams said, adding: “The police who have heard this story understand what the [victim] was saying, but doubt that he could really understand what they were saying.” 
 
 Later in the day, New York City Police Commissioner Ray Kelly downplayed the Manhattan reference. When asked on CNN’s “The Situation Room” whether he had heard from authorities that the suspects were aiming to bring a pressure cooker bomb or other such devices into Manhattan, he responded, “Absolutely not. Not the case.” 
 
 Katie Glueck contributed to this report.
– After hijacking a car, the Boston bombing suspects chose not to kill its driver—because he's not an American, he told police. Pete Williams of NBC reported the news, picked up by Politico; it matches a police report obtained by the Wall Street Journal. That report alleges the Tsarnaev brothers hijacked the Mercedes SUV at gunpoint about 40 minutes after killing an MIT police officer. One of them directed the driver to head to Watertown while the other brother followed in a Honda. Upon arriving there, they told the man to move to the passenger seat, transferred luggage into the car, then all set off in the SUV. They "declared to (the victim) that they were the Boston Marathon bombers and would not kill him because he wasn't American," the report says. The victim managed to escape when the brothers stopped for snacks.