(CBS News) Following the twin blasts at the Boston Marathon that has claimed two lives and dozens injured, a Saudi national is being held in custody in relation to the incident who was near the scene of the blast, CBS News correspondent John Miller reported.
Law enforcement sources told Miller a witness saw a person acting suspiciously when the explosions happened along the marathon route.
"They see him running away from the device," said Miller. "Now, a reasonable person would be running away. But this person had noticed him before. This is a civilian -- chases him down, tackles him, turns him over to the Boston police. The individual is being looked at [and] was suffering from burn injury. That means this person was pretty close to wherever this blast went off, but not so close as to suffer the serious injuries that other people did."
Authorities told Miller that the person in custody is not charged and not under arrest. He is being cooperative, answering their questions, and denying involvement. They'll likely be going over this person's communications and examine every aspect of his life, as well as talk to the witness who tackled him to find out what the person of interest did that seemed suspicious.
"So if that individual pans out that," said Miller, "that of course,it gives the case a big jump forward. If not, then they're back to physical evidence, forensics, witnesses, and whatever they can pick up on those surveillance cameras."
As for what authorities will be looking for in the crime scene area, Miller said that they will look for what they can pick up on those two devices that detonated.
"Were they command detonated, meaning was somebody standing in between them with a remote control?" Miller explained. "Were they controlled by a cell phone, where somebody could have been watching the finish line on television and detonated? Or were they carefully timed? And that would be a challenge to have them timed to go off so close together and to place them in those places without them being detected as suspicious."