WASHINGTON, April 17 (RIA Novosti) – A lid to a kitchen pressure cooker that may have been used in Monday’s Boston Marathon bombings was found on the rooftop of a building near the scene, federal law enforcement officials said Wednesday, according to US media reports, the newest clue in the twin blasts that killed three people and injured 183 others on Monday.
Federal investigators say they now believe two ordinary, 1.6 gallon (6 liter) kitchen pressure cookers, packed for maximum impact with nails, ball bearings and black powder were used to make the bombs, which exploded within seconds of each other near the finish line of the marathon.
Both explosive devices were stuffed into black bags that were left on the ground at the scene, a source close to the investigation told The Associated Press. They could have been detonated using something as simple as a kitchen timer or an alarm clock, said officials.
"That person or those people did everything they could to create a bomb that damaged and injured as many people as they possibly could," said former Navy surgeon Gary Schwendig in an interview with ABC News.
Authorities have identified the third fatality from the bombings as Lu Lingzi, a Chinese graduate student at Boston University according to China’s state-run Shenyang Evening News. She was reportedly watching the race near the finish line when the blasts occurred.
The bombs also killed 8-year-old Martin Richard and 29-year-old Krystle Campbell, both residents of Massachusetts.
Investigators said more than 2,000 tips have come in, and they are asking anyone who may have taken photos or videos near the scene, or who may have information about those responsible, to come forward.
“It’s our intention to go through every frame of every video that we have to determine exactly who was in the area,” said Boston Police Commissioner Edward Davis at a news briefing.
On the day of the race, “This was probably one of the most well-photographed areas in the country,” he added.
US President Barack Obama is expected to travel to Boston on Thursday to attend a memorial service for the victims.