FBI appeals for help in identifying 2 seen toting bags on video

BOSTON - The FBI released images Thursday of two men it wants to question in connection with the Boston Marathon bombings.

The images, taken near the finish line of the 119-yearold footrace where the bombs went off, show two men - one in a white cap worn backward and one in a black cap - whom the FBI described as suspects in the bombings, which killed three and injured more than 180 on Monday afternoon.

“Today we are enlisting the public’s help to identify the two suspects,” said Richard DesLauriers, the special agent in charge of the FBI’s Boston field office.

The man in the white cap is seen setting down a backpack at the site of one of the blasts, DesLauriers said.

Videos and photographs of the men wanted for questioning were posted online at fbi.gov.

Within moments of the announcement, the FBI website temporarily crashed, perhaps because of a crush of visitors.

The two men are considered armed and extremely dangerous, DesLauriers said, and people who see them should not approach them.

“Do not take any action on your own,” he warned.

The images were released hours after President Barack Obama and first lady Michelle Obama attended an interfaith service at a Roman Catholic cathedral in Boston to remember the people injured and killed Monday in the twin blasts near the marathon’s finish line.

Obama said at the service that “the spirit of this city is undaunted, and the spirit of this country shall remain undimmed.”

“Every one of us has been touched by this attack on your beloved city, every one of us stands with you,” Obama said in emotional remarks at Boston’s Cathedral of the Holy Cross. He spoke in often personal terms about Boston - he attended Harvard Law School in nearby Cambridge - and ended with a rousing look forward to next year’s Boston Marathon.

As the president sought to console a shaken Boston, and a shaken nation, investigators continued to pursue the bombers. Investigators have found clear video images of two potential suspects carrying black bags, one at the site of each explosion, a person briefed on the investigation said. The men appeared to capture the interest of law-enforcement officials because of their bags: Crime-scene investigators recovered portions of a shredded black backpack that they believe carried explosives, the person said, and they were able to determine the brand and model of the bag. The backpack carried by at least one of the men seen in the videos appeared to be similar, the person said.

In Washington, Janet Napolitano, the secretary of the Department of Homeland Security, addressed the attacks, telling a congressional committee that authorities are seeking to speak with “individuals” spotted in video footage.

“We have been collecting video from a variety of sources, as you might imagine, at the finish line of the Boston Marathon,” she said. “There’s lots and lots of video. There is some video that has raised the question of those that the FBI would like to speak with. I wouldn’t characterize them as suspects under the technical term. But we need the public’s help in locating these individuals.”

Video and photos recovered in the investigation are being examined and enhanced by an FBI unit called the Operational Technologies Division, said Joe DiZinno, former director of the FBI laboratory in Quantico, Va.

Investigators are looking at video frame by frame - a laborious process, though one aided by far more sophisticated facial recognition technology than is commercially available, forensic specialists said.

The investigation will probably collect about 1 million hours of videotape from fixed security cameras, cell phones and cameras used by spectators, said Gene Grindstaff, a scientist at Intergraph Corp., a Huntsville, Ala., company that makes video analysis software used by the FBI and other law-enforcement agencies.

DiZinno, who ran the FBI lab from 2007 to 2010, said any retrieved bomb components such as the recovered pressure cookers, shrapnel and pieces of timers or wire will be closely examined for fingerprints, DNA, hairs and fibers.

The bomb components would be traced by figuring out the item’s maker, where each piece is typically purchased and whether the device resembles any bombs the FBI has seen in past attacks. The FBI lab keeps a detailed file on past bombings, including many overseas attacks.

“Let’s say there was a timer,” DiZinno said. “Was there a serial number? Who was the manufacturer? That can provide leads for investigators.”

The interfaith “Healing Our City” service where Obama spoke brought together Christian, Muslim and Jewish religious leaders, as well as prominent state and local leaders. Mitt Romney, the former governor of Massachusetts and Obama’s rival in last year’s presidential election, was among the dignitaries at the service.

“Boston is the perfect state of grace,” said the president, quoting a poetic description of the city that was torn by the blasts. “In an instant the day’s beauty was shattered. A celebration became a tragedy.

“And so we come together to pray and mourn and measure our loss,” Obama said. “But we also come together today to reclaim that state of grace. To reaffirm that the spirit of this city is undaunted and the spirit of the country shall remain undimmed.”

For Obama, who has attended services and memorials for tragedies in Newtown, Conn., Aurora, Colo., and Tucson, Ariz., the visit to Boston was just his latest task in seeking to help a nation heal while resolutely looking ahead.

“We may be momentarily knocked off our feet, but we’ll pick ourselves up, we’ll keep going. We will finish the race,” he said.

“We finish the race, and we do that because of who we are,” the president said to applause. “And that’s what the perpetrators of such senseless violence - these small, stunted individuals who would destroy instead of build and think somehow that makes them important - that’s what they don’t understand.”

He warned those behind the attack: “We will find you.”

Boston’s long-serving mayor, Thomas Menino, who recently announced that he would not seek a sixth term, got out of the wheelchair he has been using because of a broken leg and stood at the lectern to proclaim, “We are one Boston,” adding that he had never loved the city’s people more. And Gov. Deval Patrick of Massachusetts said that “we will have accountability without vengeance, vigilance without fear.”

Seven victims remained in critical condition. Killed were 8-year-old Martin Richard of Boston, 29-year-old restaurant manager Krystle Campbell of Medford, Mass., and Lu Lingzi, a 23-year-old Boston University graduate student from China.

At a Senate hearing Thursday morning, the nation’s top intelligence official, James Clapper Jr., echoed Obama’s comments earlier this week that authorities still do not know whether the attack was a foreign or domestic plot, carried out by one or more individuals or a group.

In a brief interview after the hearing, Clapper, the director of national intelligence, said all of the nation’s 16 intelligence agencies are supporting the FBI-led investigation, with personnel as well as analytical and technical know how.

“We will bring all the resources that they need,” said Clapper, who declined to provide details.

Obama spoke in personal terms about the victims of the bombing and offered prayers for their families.

Krystle Campbell was “always smiling,” he said, noting that her parents were at the service. He said that his prayers were with the family of Lu Lingzi, who had sent her to graduate school in Boston “so that she could experience all that this city has to offer.” And he spoke about Martin Richard of Dorchester, killed in a blast that also wounded his mother and sister.

“His last hours were as perfect as an 8-year-old boy could hope for: with his family, eating ice cream at a sporting event,” the president said. Information for this article was contributed by Katharine Q. Seelye, Michael Cooper, John Eligon, Richard A. Oppel Jr., Jess Bidgood, William K. Rashbaum, Scott Shane, Michael S. Schmidt and Eric Schmitt of The New York Times; by Adam Geller, Denise Lavoie, Jay Lindsay, Pat Eaton-Robb, Steve LeBlanc, Bridget Murphy, Meghan Barr, Jeff Donn, Julie Pace, Eileen Sullivan, Lara Jakes, Curt Anderson and Marilynn Marchione of The Associated Press; and by Michael Muskal and Molly Hennessy-Fiske of the Los Angeles Times.