From the Baker Institute Blog:
Following the death of a Colorado prison official, two Texas prosecutors, and the killing of an intruder at the home of a Colorado prosecutor, speculation about the nature of the attacks has been rampant. There have been three general theories about the attacks: (1) the attacks are the personal vendetta of an individual or individuals prosecuted by these officials, (2) the attacks are the work of the Texas Aryan Brotherhood, and (3) the attacks are the work of Mexican cartels.
Read it all here.