Maryland v. King Buccal (2013)
DNA testing/swab of arrestees = search
At least for serious felonies - they can do without individualized suspicion or warrant
McNeely v. Missouri
4th am. protection against warrantless searches applies to blood alcohol tests unless specific exigent circumstances exist.
Because each case must be considered based on its individual facts, there are cases in which the natural dissipation of alcohol in the blood would be considered an exigent circumstance, but no reason to create a categorical rule.
Tennessee v. Gardner (1985)
Winston v. Lee
Rochin v. California