Investigators are appealing to the public to come forward with photos, videos, or any clues that could help solve the Boston Marathon bombings.
The FBI has circulated information about the bombs, which involved kitchen pressure cookers packed with explosives, nails and other lethal shrapnel — but authorities say so far nobody has claimed responsibility for Monday's attack.
At a news conference Tuesday the FBI said witnesses could have seen a bomber carrying an unusually heavy nylon bag, weighed down with shrapnel-packed explosives.
A television station is reporting that police are searching an apartment in a Boston suburb, and authorities confirm the search is part of the investigation into the explosions near the finish line of the Boston Marathon.
WBZ-TV reports that police are searching the apartment in Revere. Massachusetts State Police confirmed that a search warrant was served Monday night but provided no further details.
The FBI is leading the investigation into the explosions, which killed three people and injured more than 140 others.
President Barack Obama, responding to the explosions at the Boston Marathon, says the United States does not know "who did this or why" but vowed that whoever is responsible "will feel the full weight of justice."
He said: "We will find out who did this and we will hold them accountable."
Obama made his remarks Monday evening from the White House about three hours after two explosions detonated near the marathon's finish line. At least three people were killed and more than 100 injured in the blasts.
Enemies: A History of the FBI is the first definitive history of the FBI’s secret intelligence operations, from an author whose work on the Pentagon and the CIA won him the Pulitzer Prize and the National Book Award.
We think of the FBI as America’s police force. But secret intelligence is the Bureau’s first and foremost mission. Enemies is the story of how presidents have used the FBI as the most formidable intelligence force in American history.
Here is the hidden history of America’s hundred-year war on terror. As a correspondent for The New York Times, Tim Weiner he covered the Central Intelligence Agency in Washington and terrorism in Afghanistan, Pakistan, the Sudan, and other nations. Enemies is his fourth book. Weiner will be speaking tomorrow at the Carey Center for Global Good in Rensselaerville.