Police get break with video footage of possible bomb suspect

CTV National News: Searching for clues Paul Workman explains how a department store camera may offer a significant lead for police, as they look for clues into the bombings.

While the FBI and Boston Police had to deny reports Wednesday that a suspect was arrested in the Boston Marathon attack, it appears they have uncovered video surveillance footage of a man dropping off a bag at the scene of the bombing.

The twin bombings, which were set off close to the finish line of the annual Boston Marathon, killed three people and wounded more than 170. Some remain in critical condition.

Law enforcements officials confirmed late Wednesday to U.S. media that authorities have found an image of a potential suspect but don't know his name.

This confirmation came after media reports earlier in the day that an arrest had been made, leading to a confusing scene outside a Boston courthouse.

“Despite reports to the contrary there has not been an arrest in the Marathon attack,” Boston Police tweeted shortly after 2:30 p.m. local time on Wednesday.

Soon after, the FBI posted a statement to its website.

“Contrary to widespread reporting, no arrest has been made in connection with the Boston Marathon attack,” the agency said.

“Over the past day and a half, there have been a number of press reports based on information from unofficial sources that has been inaccurate. Since these stories often have unintended consequences, we ask the media, particularly at this early stage of the investigation, to exercise caution and attempt to verify information through appropriate official channels before reporting.”

The denials followed a flurry of conflicting reports Wednesday afternoon about whether a suspect had in fact been arrested.

The arrest speculation began not long after the release of surveillance video taken from outside the Lord and Taylor department store that appeared to show a man placing a package on the sidewalk outside the store, then walking away. The second explosion occurred just outside the store.

The man is seen clearly in the footage, which has been enhanced by video forensics experts. The video may have been recorded by the department store's security cameras.

This image matched the findings with witness descriptions of someone leaving the scene.

Also Wednesday, it emerged that investigators have recovered part of a circuit board believed to have been used in one of the two bombs detonated in Boston on Monday. They also found the lid of a pressure cooker they think housed one of the deadly devices.

The twin bombings, which were set off close to the finish line of the annual Boston Marathon, killed three people and wounded more than 170. Some remain in critical condition.

A law enforcement official, who spoke on condition of anonymity because they were not authorized to speak to the media, confirmed to The Associated Press Wednesday that investigators have recovered what they believe are some of the pieces of the explosive devices.

It had been revealed Tuesday that the bombs had been contained in pressure cookers -- large, sealed pots that serve to make a 'low explosive' bomb even deadlier by allowing pressure to build before the blast goes off.

Investigators asked for help from the public, urging anyone with video or still images of the area from the day of the bombing or the days leading up to it to contact police, even if they don't think the images contain any important information. There have been thousands of submissions for them to sort through.

As of Wednesday, at least 14 bombing victims, including three children, remained in critical condition. Dozens of victims have been released from hospitals, and officials at three hospitals that treated some of the most seriously injured said they expected all their remaining patients to survive.

A 2-year-old boy with a head injury was improving and might go home Thursday, Boston Children's Hospital said. The trauma surgery chief at Boston Medical Center said most injuries dealt with at his hospital were to the lower 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."

At Massachusetts General Hospital, four amputations were performed -- all above the knee, 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 blasts killed 8-year-old Martin Richard, of Boston, and 29-year-old Krystle Campbell, of Medford.

The third victim was identified by police as Lu Lingzi, a graduate student from China who was attending Boston University.