The McLennan County DA's office has asked the Texas AG to take over a routine embezzlement case because the DA has a long standing personal relationship with the defendant.  As you can imagine, personal conflicts - especially in small areas - happen everyday.  The culture of prosecution, however, is to avoid recusal wherever possible.  Prosecutors figure that they have a job to do even if it cuts close to the bone, but sometimes the cut is just too cut and referrals are in order.  Sometimes it is to another DA and sometimes it is to the AG's office where many states maintain a small criminal trial unit to handle conflicts and complex cases from rural areas.  Some states - including my own State of Maine - handle all of a certain sort of case such as homicides in order to increase both the consistency and the quality of expert testimony.