One Boston Bombing Suspect Is Dead, Second at Large; Area on Lockdown   Police searched for a suspect on Friday in Watertown, Mass. By KATHARINE Q. SEELYE and MICHAEL COOPER BOSTON — One of the suspects in the Boston Marathon bombings was killed early Friday morning after leading the police on a wild chase that resulted in the death of a campus police officer, while the other was sought in a massive manhunt that shut down large parts of the area. And Gov. Deval Patrick of Massachusetts said residents of Boston and its neighboring communities should “stay indoors, with their doors locked.” The two suspects were identified by law enforcement officials as brothers from Chechnya. The surviving suspect was identified as Dzhokhar A. Tsarnaev, 19, of Cambridge, Mass., a law enforcement official said. The one who was killed was identified as his brother, Tamerlan Tsarnaev, 26. The manhunt for the surviving bombing suspect sent the Boston region into the grip of a security emergency: residents of the city and the surrounding area were urged to stay indoors, as hundreds of police officers conducted a manhunt and all public transit services was suspended. Col. Tim Alben of the Massachusetts State Police said investigators believed that the two men were responsible for the death of Massachusetts Institute of Technology police officer and the shooting of an officer with the Massachusetts Bay Transportation Authority, the region’s transit authority. “We believe these are the same individuals that were responsible for the bombing on Monday at the Boston Marathon,” he said. Officials said the two men were from Chechnya, a long-disputed, predominantly Muslim territory in southern Russia that fought two bloody wars in the 1990s against Russian authorities. The family lived briefly in Makhachkala, the capital of the Dagestan region, near Chechnya, before moving to the United States, said a school administrator there. Irina V. Bandurina, secretary to the director of School No. 1, said the Tsarnaev family left Dagestan for the United States in 2002 after living there for about a year. She said the family — parents, two boys and two girls — had lived in the Central Asian nation of Kyrgyzstan previously. Both brothers have substantial presence on social media. On Vkontakte, Russia’s most popular social media platform, the younger brother, Dzhokhar, describes his worldview as “Islam” and, asked to identify “the main thing in life,” answers “career and money.” He lists a series of affinity groups relating to Chechnya, and lists a verse from the Koran, “Do good, because Allah loves those who do good.” The older brother left a record on YouTube of his favorite clips, which included Russian rap videos, as well as testimonial from a young ethnic Russian man titled “How I accepted Islam and became a Shiite,” a clip titled “Seven Steps to Successful Prayer.” Early Friday, a virtual army of heavily armed law enforcement officers was still going through houses in Watertown, outside of Boston, one by one in a search for the second suspect. The police had blocked off a 20-block residential area and urged residents emphatically to stay inside their homes and not answer their doors. The Boston police commissioner, Ed Davis, said: “We believe this to be a man who’s come here to kill people, and we need to get him in custody.” With gunfire ricocheting around the tranquil neighborhood, residents were later told to go into their basements and stay away from windows. The pursuit began after 10 p.m. Thursday when two men robbed a 7/11 near Central Square in Cambridge. A security camera caught a man identified as one of the suspects, wearing a gray hoodie. About 10:30, police received reports that a campus security officer at M.I.T. was shot while he sat in his police cruiser. He was found with multiple gunshot wounds, according to a statement issued by the acting Middlesex district attorney, Michael Pelgro, Cambridge Police Commissioner Robert Haas, and the M.I.T. police chief, John DiFava. The officer was taken to Massachusetts General Hospital, where he was pronounced dead.   New York Times