BOSTON - From word of an arrest to an absolute denial from top government officials, Wednesday proved to be a chaotic day in the search for the person(s) behind the Boston Marathon bombings.
Earlier in the day CNN reported it had confirmed reports of an arrest.
A short time later, the Associated Press reported that a suspect was to be taken into custody by federal marshals and taken to a Boston courthouse. The AP sourced an unidentified official.
As word spread, a large crowd gathered outside the courthouse to get a glimpse of the suspect.
Then the Department of Justice and Boston Police released word saying there was no such arrest made.
But the FBI and the U.S. attorney's office in Boston disputed that.
The official who spoke to The Associated Press did so on condition of anonymity and stood by the information, even after it was disputed.
Investigators would confirm that a suspect had been spotted on surveillance video taken at a Lord & Taylor store between the two bomb blasts.
Earlier Wednesday morning, investigators circulated information about the bombs, which involved kitchen pressure cookers packed with explosives, nails and other lethal shrapnel. But the FBI said nobody had claimed responsibility.
A person close to the investigation had previously told the AP that the bombs consisted of explosives put in 1.6-gallon pressure cookers, one with shards of metal and ball bearings, the other with nails.
Investigators in white jumpsuits had fanned out across the streets, rooftops and awnings around the blast site in search of clues on Wednesday. They combed through debris amid the toppled orange sports drink dispensers, trash cans and sleeves of plastic cups strewn across the street at the marathon's finish line.
President Barack Obama branded the attack as an act of terrorism. The President and First Lady plan to attend an interfaith service Thursday in the victims' honor in Boston.
Scores of victims of the Boston bombing remain in hospitals, many with critical injuries. Doctors who treated the wounded corroborated reports that the bombs were packed with shrapnel intended to cause mayhem.
The trauma surgery chief at Boston Medical Center says most of the injuries his hospital treated after the marathon bombings were to the legs.
"We have a lot of lower extremity injuries, so I think the damage was low to the ground and wasn't up," Dr. Peter Burke said. "The patients who do have head injuries were blown into things or were hit by fragments that went up."
Dozens of patients have been released from hospitals around the Boston area.
At Massachusetts General Hospital, all four amputations performed there were above the knee, with no hope of saving more of the legs, said Dr. George Velmahos, chief of trauma surgery.
"It wasn't a hard decision to make," he said Tuesday. "We just completed the ugly job that the bomb did."
The bombs exploded 10 or more seconds apart, tearing off victims' limbs and spattering streets with blood. The blasts near the finish line instantly turned the festive race into a hellish scene of confusion, horror and heroics.
The blasts killed 8-year-old Martin Richard, of Boston, and 29-year-old Krystle Campbell, of Medford and Lu Lingzi. She was a graduate student at Boston University.
Associated Press writers Eileen Sullivan in Washington; Jay Lindsay, Pat Eaton-Robb, Steve LeBlanc, Bridget Murphy, Rodrique Ngowi and Meghan Barr in Boston; Julie Pace and Lara Jakes in Washington; Paisley Dodds in London; Lee Keath in Cairo; and Marilynn Marchione in Milwaukee contributed to this report along with investigative researcher Randy Herschaft in New York.