Why were the feds involved?

I have heard people asking the question, "Why were the feds involved in the Boston Marathon bombing investigation and manhunt?"

The answer to the question of federal involvement may be contained in this response from AG Eric Holder to Senator Rand Paul - “'Does the president have the authority to use a weaponized drone to kill an American not engaged in combat on U.S. soil?' The answer to that question is no."

Apparently the Boston Marathon bombers were engaged in combat on U.S. soil (i.e., asymmetrical warfare combat a.k.a. acts of terrorism). Under the Obama/Holder doctrine, the feds have the authority to track them down anywhere in the world (including on U.S. soil) and kill them using a weaponized drone or other means. This was perhaps the first application of that doctrine since Holder made his statement, and it is further being justified by attempts to link the brothers to al Qaeda.

Rand Paul's concerns are now water under the bridge. It's only a matter of time until weaponized drones are deployed in the skies of the US, and many people will be relieved and/or happy when that time comes.

Skynet is just around the corner.