More details in Boston bombings surface as investigation intensifies

Posted at 9:37 AM, Apr 17, 2013
and last updated 2013-04-17 09:37:26-04

(CNN) — Within a day of the Oklahoma City bombing, officials had named their suspect: Timothy McVeigh. Within two days of the 9/11 attacks, investigators had zeroed in on al Qaeda as the perpetrator.

But as loved ones mourn the deaths of three people and dozens remain hospitalized from dual bombings at the Boston Marathon, two questions continue to hound authorities: Who triggered the attack, and why?

On Wednesday morning, a federal law enforcement source with firsthand knowledge of the investigation told CNN’s Fran Townsend that a lid to a pressure cooker thought to have been used in the bombings had been found on a roof of a building at the scene.

While such clues move the investigation forward, even for seasoned investigators, the theories run the gamut on whether Monday’s attack was an act of domestic or foreign terrorism.

All of the talking heads that discuss this incident and incidents like it, if your experience and your expertise is Middle East terrorism, it has the hallmarks of al Qaeda or a Middle East group. If your experience is domestic groups and bombings that have occurred here, it has the hallmarks of a domestic terrorist like Eric Rudolph in the 1996 Atlanta Summer Olympics bombings,” former FBI Assistant Director Tom Fuentes said.

“I’ve been to both. I’ve run bomb scenes in Iraq and also in the U.S. It has the hallmarks of both domestic and international (attacks), and you can see either side of that.”

While the answers remain uncertain, new information continues to surface.