Third victim identified
Boston University identified graduate student Lingzu Lu as the third person who died in Monday's bombings.
Previously identified were Krystle Campbell, 29, of Arlington, Massachusetts, and Martin Richard, 8, of Dorchester, Massachusetts.
"She was the best," Campbell's distraught mother, Patty, told reporters Tuesday. "You couldn't ask for a better daughter."
Martin "was a bright, energetic young boy who had big dreams and high hopes for his future," his school said in a statement. "We are heartbroken by this loss."
The hunt for the attacker
The attack left Boston police with "the most complex crime scene that we've dealt with in the history of our department," Commissioner Ed Davis said Tuesday.
Authorities sifted through thousands of pieces of evidence and a mass of digital photos and video clips. They have pleaded for the public's help in providing additional leads and images.
"Someone knows who did this," said Rick DesLauriers, the special agent in charge of the FBI's Boston office, said. "The community will play a crucial role in this investigation."
Medical personnel treating the wounded found evidence suggesting the bomb maker or bomb makers sought to maximize the suffering.
Dr. George Velmahos, head of trauma care at Massachusetts General Hospital, said his team found "numerous" metal pellets and nails inside patients' bodies.
"There are people who have 10, 20, 30, 40 of them in their body, or more," Velmahos said.
Dr. Ron Walls also said one patient had more than 12 carpenter-type nails.
"There is no question some of these objects were implanted in the device for the purpose of being exploded forward," he said.
Victims continue recovery
As investigators continued to search for a suspect, those wounded in the incident continued to recover.
Boston-area hospitals had released at least 112 of the 178 people injured in the attack, according to CNN's tally late Wednesday. Of the 66 people who were still hospitalized, 13 were in critical condition.
Boston Medical Center has two patients in critical condition, down from 11 just after the bombings, Dr. Peter Burke, chief of trauma care, told reporters Wednesday. Ten patients are in serious condition and seven are in fair condition, he said.
Spectator Steve Byrne was standing with a group of friends near a mailbox when the second blast went off. Now his face is scarred with shrapnel wounds. A BB pellet remains lodged in his neck. Doctors said they couldn't remove it because was too close to nerves that control his vision, but he was out of the hospital on Wednesday.
Compared to how his friends are suffering, he told CNN's AC360 that he feels lucky.
Four out of the five friends he was watching the marathon with have lost limbs, he said. One friend had 70 nails in his leg.
He remembers the explosion in vivid detail: the blast that was so strong that it burned his clothes off; the carnage around him; and the haunting, slow-motion daze of searching for his friends.
"We were having a great day and waiting to see our friend cross the finish line," he said, "and then all of the sudden it turned in a flash."
He told CNN he's worried about the financial burdens his friends could face as a result of the explosion.
One friend is a carpenter and "both his hands are incinerated. He can't go to work, and the bills keep coming in."