What we know about the Boston Marathon bombing and its aftermath

CNN  — 

New developments:

– The third victim is identified as a Chinese national who was a graduate student at Boston University. China’s consulate in New York said the student’s name was not made public at her family’s request. When the explosions occurred, the victim was watching the race near the finish line with two other students – one of whom is in stable condition at Boston Medical Center after two surgeries each of the past two days, while the other emerged unharmed.

– “The range of suspects and motives remains wide open,” Richard DesLauriers, special agent in charge of the FBI’s Boston office, said late Tuesday afternoon. More than 1,000 law enforcement officers will go to the “ends of the Earth” to find the perpetrators, he said.

– Limbs were amputated in the treatment of 13 people, who were among the 183 injured treated at 11 Boston-area hospitals.

Previously reported:

– Three people died and scores were hurt in two bomb blasts, 12 seconds apart, that erupted near the finish line of Monday’s Boston Marathon, police said.

– At least nine of the wounded are children.

The investigation:

– The Department of Homeland Security issued an advisory about pressure-cooker bombs in 2004. Bombs are made by placing TNT or other explosives in a pressure cooker and attaching a blasting cap at the top of the pressure cooker, the advisory said. “The size of the blast depends on the size of the pressure cooker and the amount of explosive placed inside. Pressure cooker bombs are made with readily available materials and can be as simple or as complex as the builder decides. These types of devices can be initiated using simple electronic components including, but not limited to, digital watches, garage door openers, cell phones or pagers.”

– President Barack Obama said officials do not know whether the bombing was the work of a terrorist group or “a malevolent individual,” nor do authorities have a sense of what may have been the motive.

– “We will find whoever harmed our citizens and we will bring them to justice,” he said.

– A senior U.S. official told CNN, “There is no reporting indicating a foreign connection, or any reaction from al Qaeda.” The official said that is based on information circulated through senior levels of the administration earlier Tuesday, and it could change as the investigation progresses.