“The new law now mandates blood be drawn from citizens in a variety of circumstances. No longer limited to vehicular assault cases, police are [now] required to take the blood of any DUI suspect who has ever had a DUI conviction in their life, according to WBIR. The other requirement is that blood be drawn from any suspect who has a person under the age of 16 in the car. The rest of the blood-draw cases are done upon seeking a readily available warrant. In light of these new powers, the latest fad in Tennessee law enforcement is setting up ‘no refusal’ checkpoints, having a judge or a judicial commissioner on call to churn out blood warrants on demand.”
http://www.policestateusa.com/2013/tennessee-roll-refusal-blood-draw-dui-checkpoints-labor-day/