As I write this, investigators – the best of the best in law enforcement – are working round the clock gathering evidence, interviewing hundreds of witnesses, watching surveillance video and viewing photos to gather critical evidence about the two blasts that ripped through a crowd as runners streamed to the finish line of the Boston Marathon
At the same time, authorities will learn vital information from the evidence about who’s responsible for killing three, including an 8-year-old boy, and wounding upwards of 140 people.
The two home-made bombs, which authorities have said appear to have been placed inside backpacks and left in trash barrels, left thousands scrambling for cover.
What experts will also be looking for is a signature of sorts.
Those who make devises like this “oftentimes find what is comfortable for them to build, then pretty much repeat the device,” said Don White, who for 18 years was with the Bexar County Sheriff’s Department’s homicide investigation division in San Antonio, Texas. “I would think one of the primary criteria is being able to make a device that works, without blowing up the maker.”
As hours pass since the explosions on Boston’s Patriots’ Day, investigators will learn more, gleaning invaluable evidence that should lead them to the person or person’s behind it. “With the number of cameras that were out there,” White said, “they might get a glimpse of someone. There is a good chance they will identify someone. (But) it may not be quick.”
City, state and federal officials, led by the FBI, know so far that it was an act of terrorism and the bombs spewed ball bearings that reacted as shrapnel, ripping through the crowd. The bombs were small, said White, but they were “placed for maximum effect, and that doesn't always mean maximum death counts, but (rather) large numbers of injured.”
Fragments of shrapnel from the scene as well as shrapnel removed from victims will be analyzed to determine if the person responsible is a bomb maker or an amateur. Authorities are also collecting security video from the scene and poring over the footage as well as photos, searching for more vital clues.
“They’ll look through videotape from all the video available in that neighborhood to see if anyone stands out or looks suspicious,” Richard Clarke, a counter-terrorism advisor following 9/11, told ABC’s “Nightline.”
For those heinous actions, President Barack Obama, speaking at the White House Monday, vowed to bring the "full weight of justice" down on who is responsible for the attacks. “Make no mistake,” Obama said. “We will get to the bottom this.”
According to officials who spoke to Reuters on condition of anonymity, two theories have emerged about who might be behind the explosions. The first, based in part on the timing of the bombings, on tax day when U.S. citizens file their returns, and also on Patriots' Day, points to domestic anti-government or anti-tax activists possibly planning the attacks.
The second theory, according to Reuters’ source, points to Islamic militants possibly connected, because of the similarities between what is known about the attacks -- two explosions in close proximity within seconds of the other to at a high-profile event – as a way of carrying out an attack.
Inspire, a publication circulated on the Internet by Yemen-based al Qaeda in the Arabian Peninsula, recently included a supplement that had instructions on how to perform various attacks and how to build homemade devices, according to Reuters.
It’s an example of a possible signature clue authorities are looking for as they scour the evidence that will lead them to a perpetrator.