As for theories involving this series of events, I don't have enough information. There are a variety of viable possibles that have already been floated on this and other threads, including terrorist activity, gang initiations, and thill-kills, although the precision with which this has been conducted would indicate the first postulate more than anything else.
It is also noteworthy that the perps purposefully chose one of the most heavily disarmed areas of our nation in which to conduct their operations. This would give them a longer lifespan, although, if terrorists, I would fully expect such creatures to anticipate dying during the course of their attacks, which gives them another added advantage.
The anxiety that this series of attacks has inspired is exactly what terrorism seeks to accomplish: to destabilize the inhabitants of a society, have them constantly distrustful, worried, and angry with a government that obviously cannot protect them. Civilized society is based on trust -- trust that the person next to you will not arbitrarily seek to harm you, and that they can think likewise. When that is dissolved, so is the society.
One thing is clear: It is the duty of each and every citizen to stay alert, stay armed and take the proper steps in their own defense in situations such as these. Anyone ditty-bopping around in condition white expecting the "authorities to take care of everything" faces a much greater probability of winding up in a bag.
