Joe--I'm going to post this question in the pretrial release forum in hopes more people will see and respond to your question. I'm not sure how common it is any more that pretrial agencies conduct home visits. I would suspect that it depends on the level of risk the defendant poses and the conditions of bail the court set. The authority to detain would most likely depend on how the program is administered, such as a jail based program. The issue of detaining a defendant for non-compliance could also be a sensitive issue as well. I know in many jurisdictions, a judicial officer is the only one that can make detention decisions pending trial.